A method for controlling a fluidic precooling smoothing

Abstract

The application belongs to the technical field of aerospace, and particularly relates to a jet precooling smooth control method, which realizes accurate metering control in a transition state through smooth control in a switching process, solves rapid and accurate filling of a long pipeline, shortens jet precooling delay time, speeds up closed-loop response of an engine inlet total temperature, solves the problem that a water flow control device is too far from a jet precooling nozzle pipeline of an air inlet, needs a long filling time, and when a new opening area still does not supply water, the original opening area has reduced water supply according to a new distribution scheme, resulting in sudden reduction of total water supply; and solves the problem that when a certain area increases water flow and another area reduces water flow, the opening and closing rates of corresponding metering valves do not match, resulting in inaccurate water supply for a certain period of time.

Description

Technical Field

[0001] This application belongs to the field of aerospace technology, and specifically relates to a jet precooling smooth control method. Background Technology

[0002] In recent years, a great deal of research has been carried out both domestically and internationally on jet precooling expansion lines for turbine engines. This involves installing a water spray precooling device in the intake manifold, injecting atomized liquid water into the intake manifold, and reducing the total temperature of the engine inlet through water evaporation and heat absorption.

[0003] The China Aero Engine Research Institute actively carried out research on key technologies for jet precooled engines. Using a certain type of engine as a platform, it completed the ground verification of the whole engine with jet precooling at a ground temperature of 316.7℃, verifying the technical feasibility of jet precooling to extend the envelope of the turbine engine.

[0004] The domestically developed jet precooling control system consists of a digital electronic controller, a water pump, and a control unit. The control unit integrates a three-zone electro-hydraulic servo valve, a three-zone displacement sensor, a water supply pressure sensor, and a pressure sensor after the three-zone metering valve. The jet precooling control system uses the turbine inlet total temperature as the controlled variable. The three zones employ an "outer loop + middle loop + inner loop" control scheme to improve the system's steady-state and dynamic performance. The outer loop controls the turbine inlet total temperature, the middle loop controls the metering valve outlet pressure, and the inner loop controls the metering valve displacement. The current design has two problems, as follows:

[0005] First, because the water flow control device is too far from the air intake jet pre-cooling nozzle pipeline, it requires a long filling time. There is a problem that the total water supply suddenly decreases when the newly opened area has not yet been supplied with water, while the original opened area has reduced its water supply according to the new distribution plan.

[0006] Secondly, since the metering valve also requires time to travel throughout its entire stroke, when the water flow rate increases in one zone and decreases in another zone, the opening and closing rates of the corresponding metering valves are not matched, which leads to inaccurate water supply for a certain period of time. Summary of the Invention

[0007] To address the aforementioned problems, a jet precooling smoothing control method is provided, characterized by comprising:

[0008] Step S1: Calculate the expected value T2_Dem of the engine inlet total temperature based on the aircraft Mach number.

[0009] Step S2: The deviation value Delta_T2 is obtained by subtracting the expected value T2_Dem from the total inlet temperature T2 collected by the engine inlet sensor.

[0010] Step S3: Calculate water flow target value Ww_dem based on bias value Delta_T2;

[0011] Step S4: Control water supply of each water supply sub-area according to size of water flow target value Ww_dem, each water supply sub-area at least includes first sub-area, second sub-area and third sub-area;

[0012] Specific control method includes:

[0013] Case 1: When water flow target value Ww_dem is less than a (kg / s);

[0014] Step 11: First sub-area metering valve is fully opened, and empty pipeline is filled quickly;

[0015] Step 12: When back pressure of first sub-area metering valve is greater than or equal to A (Mpa) or water volume integral of first sub-area reaches B (L), first sub-area water supply flow Ww1_dem is equal to water flow target value Ww_dem, and closed loop control is started;

[0016] Case 2: When water flow target value Ww_dem is greater than or equal to a (kg / s) and less than b (kg / s);

[0017] Step 21: If first sub-area metering valve is opened, it is kept, if first sub-area metering valve is not opened, it is opened according to the case 1, second sub-area metering valve is fully opened, and empty pipeline is filled quickly;

[0018] Step 22: When back pressure of second sub-area metering valve is greater than or equal to C (Mpa) or water volume integral of second sub-area reaches D (L), second sub-area water supply flow Ww2_dem and first sub-area water supply flow Ww1_dem are proportionally readjusted, and closed loop control is carried out;

[0019] Case 3: When water flow target value Ww_dem is greater than or equal to b (kg / s) and less than c (kg / s);

[0020] Step 31: If first sub-area metering valve is opened, it is kept, if first sub-area metering valve is not opened, it is opened according to the case 1, if second sub-area metering valve is opened, it is kept, if second sub-area metering valve is not opened, it is opened according to the case 2, empty pipeline is filled quickly, third sub-area metering valve is fully opened, and empty pipeline is filled quickly;

[0021] Step 32: When back pressure of third sub-area metering valve is greater than or equal to E (Mpa) or water volume integral of first sub-area reaches F (L), third sub-area water supply flow Ww3_dem, second sub-area water supply flow Ww2_dem and first sub-area water supply flow Ww1_dem are proportionally readjusted, and closed loop control is carried out.

[0022] Preferably, the closed-loop control method specifically comprises:

[0023] First step: calculate the water supply expectation value of each water supply sub-area based on the water supply flow and the calibrated valve opening line of each water supply sub-area;

[0024] Second step: calculate the water quantity control current of each water supply sub-area through the deviation value of the water supply expectation value of each water supply sub-area and the acquisition value of the metering valve displacement sensor;

[0025] Third step: control the opening degree of the metering valve through the water quantity control current of each water supply sub-area, and the opening degree of the metering valve and the jet pre-cooling controller of each sub-area jointly realize the control of the engine inlet multi-pipeline water flow.

[0026] Preferably, A is greater than the pressure size when the first sub-area metering valve has no water flow, and A is less than the pressure size when the first sub-area metering valve has water flow;

[0027] C is greater than the pressure size when the second sub-area metering valve has no water flow, and A is less than the pressure size when the second sub-area metering valve has water flow;

[0028] E is greater than the pressure size when the third sub-area metering valve has no water flow, and A is less than the pressure size when the third sub-area metering valve has water flow.

[0029] Preferably, B is the volume of the first sub-area water pipe, D is the volume of the second sub-area water pipe, and E is the volume of the third sub-area water pipe.

[0030] Preferably, in the case 2, Ww2_dem = Ww1_dem = Ww_dem / 2.

[0031] Preferably, in the case 3,

[0032] Ww2_dem = Ww1_dem = Ww_dem / 4.28;

[0033] Ww3_dem = Ww_dem-Ww2_dem-Ww1_dem.

[0034] Through the smooth control of the switching process, the transition state is accurately metered and controlled, and the long pipeline is quickly and accurately filled, the jet precooling delay time is shortened, the engine inlet total temperature temperature closed loop response is accelerated, the water flow control device distance from the jet precooling nozzle pipeline is too long, and a long filling time is required. When the new opening area is still not supplied with water, the original opening area has reduced the water supply according to the new distribution scheme, resulting in a sudden decrease in total water supply. The problem of sudden decrease in total water supply is solved; the problem of inaccurate water supply for a certain period of time is solved due to the movement time required for the metering valve to move through the full stroke. When the water flow of one area is increased and the water flow of another area is reduced, the corresponding metering valve opening and closing speed does not match, which leads to inaccurate water supply for a certain period of time. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a preferred embodiment of the present application jet precooling smooth control control architecture diagram

[0036] Figure 2 is a preferred embodiment of the present application jet precooling smooth control water supply partition architecture diagram. DETAILED DESCRIPTION

[0037] In order to make the technical scheme of the present application and its advantages clearer, the technical scheme of the present application will be further clearly and completely described below in combination with the drawings. It should be understood that the specific embodiments described herein are only part of the embodiments of the present application, and are only used to explain the present application, but not to limit the present application. It should be noted that, in order to facilitate description, only parts related to the present application are shown in the drawings, and other related parts can be referred to the usual design. In the case of no conflict, the embodiments in the present application and the technical features in the embodiments can be combined to obtain new embodiments.

[0038] In addition, unless otherwise defined, technical terms or scientific terms used in the description of the present application shall be understood as the common meaning understood by one of ordinary skill in the art to which the present application belongs. The words "upper", "lower", "left", "right", "center", "vertical", "horizontal", "inner", "outer" and the like used in the description of the present application only indicate relative directions or positional relationships, and do not imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and the relative positional relationship may also change accordingly when the absolute position of the described object changes, therefore it cannot be understood as a limitation on the present application. The "first", "second", "third" and the like used in the description of the present application are only for the purpose of description, in order to distinguish different components, and cannot be understood as indicating or implying relative importance. The "one", "an" or "the" and the like used in the description of the present application should not be understood as an absolute limitation on the quantity, but should be understood as the presence of at least one. The "includes" or "contains" and the like used in the description of the present application means that the elements or objects appearing before the word are covered by the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0039] In addition, it should be noted that, unless otherwise specified and limited, the "installation", "connection", "connection" and the like used in the description of the present application should be understood broadly, for example, the connection can be fixed connection, or detachable connection, or integral connection; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through intermediate medium, or the internal communication of two elements, and those skilled in the art can understand the specific meaning of the present application according to the specific circumstances.

[0040] The present application provides a kind of jet precooling smooth control method, comprising:

[0041] Step S1: the expected value T2_Dem of engine inlet total temperature is calculated according to the Mach number of aircraft,

[0042] Step S2: the deviation value Delta_T2 is obtained by subtracting the expected value T2_Dem from the inlet total temperature T2 collected by engine inlet sensor;

[0043] Step S3: the water flow target value Ww_dem is calculated based on the deviation value Delta_T2;

[0044] Step S4: according to the size of water flow target value Ww_dem, each water supply subarea is controlled to supply water, and each water supply subarea at least includes first area, second area and third area;

[0045] The specific control method comprises:

[0046] Case 1: when the water flow target value Ww_dem is less than a (kg / s);

[0047] Step 11: the first zone metering valve is fully opened, and the empty pipeline is quickly filled;

[0048] Step 12: when the back pressure of the first zone metering valve is greater than or equal to A (Mpa) or the water volume integral of the first zone reaches B (L), the water supply flow rate Ww1_dem of the first zone is equal to the water flow target value Ww_dem, and the closed-loop control is started;

[0049] Case 2: when the water flow target value Ww_dem is greater than or equal to a (kg / s) and less than b (kg / s);

[0050] Step 21: if the first zone metering valve is opened, it is maintained, and if the first zone metering valve is not opened, it is opened according to the case 1, the second zone metering valve is fully opened, and the empty pipeline is quickly filled;

[0051] Step 22: when the back pressure of the second zone metering valve is greater than or equal to C (Mpa) or the water volume integral of the second zone reaches D (L), the water supply flow rate Ww2_dem of the second zone and the water supply flow rate Ww1_dem of the first zone are proportionally readjusted, and the closed-loop control is performed;

[0052] Case 3: when the water flow target value Ww_dem is greater than or equal to b (kg / s) and less than c (kg / s);

[0053] Step 31: if the first zone metering valve is opened, it is maintained, and if the first zone metering valve is not opened, it is opened according to the case 1, if the second zone metering valve is opened, it is maintained, and if the second zone metering valve is not opened, it is opened according to the case 2, the empty pipeline is quickly filled, the third zone metering valve is fully opened, and the empty pipeline is quickly filled;

[0054] Step 32: when the back pressure of the third zone metering valve is greater than or equal to E (Mpa) or the water volume integral of the first zone reaches F (L), the water supply flow rate Ww3_dem of the third zone, the water supply flow rate Ww2_dem of the second zone, and the water supply flow rate Ww1_dem of the first zone are proportionally readjusted, and the closed-loop control is performed.

[0055] The method of the closed-loop control specifically comprises:

[0056] First step: calculating the water supply expected value of each water supply zone based on the water supply flow rate and the valve opening degree calibration line of each water supply zone;

[0057] Second step: calculating the water volume control current of each water supply zone through the deviation value of the water supply expected value of each water supply zone and the metering valve line displacement sensor acquisition value;

[0058] Third step: based on the water quantity control current of each water supply subarea, the opening of the metering valve is controlled by the electro-hydraulic servo valve, and the opening of the metering valve and the jet pre-cooling controller of each subarea jointly realize the control of the water flow of the engine inlet multi-pipeline.

[0059] For example, the case where a water flow target value Ww_dem gradually increases, the case where three water supply subareas are gradually opened, and when the first subarea is newly opened;

[0060] A is greater than the pressure when no water flow is sprayed after the first subarea metering valve, and A is less than the pressure when water flow is sprayed after the first subarea metering valve;

[0061] C is greater than the pressure when no water flow is sprayed after the second subarea metering valve, and A is less than the pressure when water flow is sprayed after the second subarea metering valve;

[0062] E is greater than the pressure when no water flow is sprayed after the third subarea metering valve, and A is less than the pressure when water flow is sprayed after the third subarea metering valve.

[0063] B is the volume of the first subarea water pipe, D is the volume of the second subarea water pipe, and E is the volume of the third subarea water pipe.

[0064] When the first subarea is opened for filling, the first subarea metering valve is fully opened to realize rapid filling, when the pressure after the first subarea metering valve is greater than or equal to A (Mpa) or the water quantity integral of the first subarea reaches B (L), Ww1_dem is equal to Ww_dem to start closed-loop control;

[0065] 2. When the second subarea is newly opened

[0066] When the second subarea is opened for filling, the second subarea metering valve is fully opened to realize rapid filling, and the first subarea still maintains the original plan unchanged.

[0067] When the pressure after the second subarea metering valve is greater than or equal to C (Mpa) or the water quantity integral of the second subarea reaches D (L), the first subarea target value Ww1_dem starts to adjust according to the new total flow ratio, and Ww_dem becomes Ww_dem / 2, at this time, the second subarea follows the master-slave control idea, Ww2_dem = Ww_dem-Ww1, which is the total water supply quantity minus the water quantity feedback of the first subarea;

[0068] 3. When the third subarea is newly opened

[0069] When the third subarea is opened for filling, the third subarea metering valve is fully opened to realize rapid filling, and the first subarea and the second subarea still maintain the original plan unchanged.

[0070] When the third zone metering valve back pressure is greater than or equal to E (Mpa) or the third zone water volume integral reaches F (L), the first zone target value Ww1_dem starts to adjust according to the new total flow ratio, from Ww_dem / 2 to Ww_dem / 4.28, the second zone target value Ww2_dem starts to adjust according to the new total flow ratio, from Ww_dem / 2 to Ww_dem / 4.28, at this time the third zone follows the master-slave control idea, Ww3_dem=Ww_dem-Ww1-Ww2, which is the total water supply minus the first and second zone water volume feedback. Set hysteresis control, that is, the entry and exit conditions of the three zones are different, which will be explained in ascending and descending order respectively.

[0071] Wherein, the values of a, b include:

[0072] 1. Gradually increasing water volume:

[0073] When Ww_dem≤1.5 kg / s, the first zone supplies water according to the control plan;

[0074] When 1.5 kg / s

[0075] When 2.96 kg / s

[0076] 2. Gradually reducing water volume:

[0077] When 1 kg / s

[0078] Ww_dem≤1 kg / s, the first zone supplies water according to the control plan.

[0079] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any changes or replacements within the technical range disclosed in the present application can be easily thought of by those skilled in the art, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method of fluidic precooling smoothing control, characterized by, include: Step S1: Calculate the expected value T2_Dem of the engine inlet total temperature based on the aircraft Mach number. Step S2: The deviation value Delta_T2 is obtained by subtracting the expected value T2_Dem from the total inlet temperature T2 collected by the engine inlet sensor. Step S3: Calculate the target water flow rate Ww_dem based on the deviation value Delta_T2; Step S4: Control the water supply of each water supply zone according to the target value of water flow Ww_dem. Each water supply zone includes at least Zone 1, Zone 2 and Zone 3. Specific methods for controlling each water supply zone include: Case 1: When the target water flow rate Ww_dem is less than a; Step 11: Fully open the metering valve in Zone 1 to quickly fill the empty pipeline; Step 12: When the pressure after the metering valve in the first zone is greater than or equal to A, or when the water volume integral in the first zone reaches B, the water supply flow rate Ww1_dem in the first zone is equal to the target water flow rate Ww_dem, and closed-loop control begins. Case 2: When the target water flow rate Ww_dem is greater than or equal to a and less than b; Step 21: If the metering valve in the first zone is open, keep it open; if the metering valve in the first zone is not open, open it according to situation 1 described above. The metering valve in the second zone is fully open to quickly fill the empty pipeline. Step 22: When the pressure after the metering valve in the second zone is greater than or equal to C, or when the water volume integral in the second zone reaches D, the water supply flow rate Ww2_dem in the second zone and the water supply flow rate Ww1_dem in the first zone are readjusted proportionally and closed-loop control is performed. Case 3: When the target water flow rate Ww_dem is greater than or equal to b and less than c; Step 31: If the metering valve in the first zone is open, keep it open; if the metering valve in the first zone is not open, open it according to situation 1. If the metering valve in the second zone is open, keep it open; if the metering valve in the second zone is not open, open it according to situation 2. Quickly fill the empty pipeline. The metering valve in the third zone is fully open. Quickly fill the empty pipeline. Step 32: When the pressure after the metering valve in the third zone is greater than or equal to E, or when the water volume integral in the first zone reaches F, the water supply flow rates Ww3_dem in the third zone, Ww2_dem in the second zone, and Ww1_dem in the first zone are readjusted proportionally, and closed-loop control is performed. Step 1: Calculate the expected water supply value for each water supply zone based on the water supply flow rate and valve opening calibration line of each water supply zone; Step 2: Calculate the water control current for each water supply zone by the deviation between the expected water supply value and the value collected by the metering valve line displacement sensor. Step 3: Based on the water volume control current of each water supply zone, the opening degree of the metering valve is controlled by the electro-hydraulic servo valve. The opening degree of the metering valve and the jet precooling controller of each zone together realize the control of the multi-pipe water flow of the engine inlet. A is greater than the pressure when there is no water flow after the first zone metering valve, and A is less than the pressure when there is water flow after the first zone metering valve. C is greater than the pressure when there is no water flow after the second zone metering valve, and A is less than the pressure when there is water flow after the second zone metering valve. E is greater than the pressure when there is no water flow after the third zone metering valve, and A is less than the pressure when there is water flow after the third zone metering valve. B represents the volume of the water pipe in the first zone, D represents the volume of the water pipe in the second zone, and E represents the volume of the water pipe in the third zone.

2. The method of claim 1, wherein the method is a method of controlling a fluidic precooling smoothening control. In case 2, Ww2_dem = Ww1_dem = Ww_dem / 2.

3. The method of claim 1, wherein the method is a method of controlling a fluidic precooling smoothening control. In case 3, Ww2_dem= Ww1_dem= Ww_dem / 4.28; Ww3_dem= Ww_dem- Ww2_dem-Ww1_dem.

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