Regenerative cooling engine thrust regulation and over-temperature treatment decoupling control method and system

Abstract

The application discloses a regenerative cooling engine thrust adjustment and over-temperature treatment decoupling control method and system, wherein after the engine is started, a controller presets reference parameters, the reference parameters including: safety temperature thresholds of each cooling oil supply subarea, and a total fuel supply reference flow of a fuel pump; during the operation of the engine, an over-temperature decoupling control module of the controller acquires real-time temperature values of the corresponding cooling oil supply subarea through a temperature sensor in real time, and determines whether to adjust the flow of each cooling oil supply subarea through over-temperature judgment; after the temperature of all the cooling oil supply subareas is the safety value, the over-temperature decoupling control module controls each supply branch to supply oil in a balanced manner under the condition that the total flow is maintained constant, so as to maintain the stable operation of the target thrust. The application can eliminate the vicious cycle of "over-temperature oil supply-thrust increase-speed increase-more over-temperature" from the root, and greatly improves the working stability and safety of the engine.

Description

Technical Field

[0001] This invention relates to the field of regenerative cooling engine design in aerospace power plants. More specifically, this invention relates to a decoupled control method and system for thrust regulation and over-temperature treatment in the operating condition control of a high-speed ramjet engine using fuel regenerative cooling, enabling precise thrust regulation during engine operation and over-temperature protection. Background Technology

[0002] As a preferred power source for high-speed aircraft, the high-speed ramjet engine features high specific impulse and high thermal load under high Mach number flight conditions. As one of the core components of high-speed aircraft, research on the mechanisms and application technologies surrounding high-speed ramjet engines has become a hot topic in recent years.

[0003] The basic structure and workflow of current mainstream regenerative cooled ramjet engines are as follows: Parallel capillary cooling channels are designed on the casings of high-temperature components such as the engine isolation section and combustion chamber, with manifolds at the inlet and outlet of each channel. The engine fuel pump outputs high-pressure, room-temperature fuel. The fuel first enters the cooling channel through the inlet manifold, absorbing heat from the high-temperature components through convective heat transfer, thus cooling them and preventing structural failure due to high temperatures. After cooling, the high-temperature fuel is collected through the outlet manifold and then passes through a high-temperature shut-off valve and fuel nozzle before finally being injected into the combustion chamber to mix and burn with the airflow. Thrust is generated through the nozzle, forming a closed-loop fuel supply mode of cooling-combustion.

[0004] Based on the inherent cooling characteristics of regeneratively cooled ramjet engines, when core components such as the isolation section and combustion chamber experience localized overheating due to excessive heat load, the conventional approach is to increase the engine fuel supply flow rate. By increasing the flow rate of cooling oil, the heat exchange effect is enhanced, thereby reducing the component temperature. However, this control method has a fundamental technical flaw: while increasing the fuel supply flow rate for overheat protection, the engine thrust also increases accordingly. Decoupling control is not possible, easily leading to a vicious cycle of overheating during refueling, increased thrust, increased flight speed, and further overheating. This has become a core pain point restricting the safe and reliable operation of regeneratively cooled high-speed ramjet engines in long-endurance, high-maneuver scenarios.

[0005] The existing technology of non-decoupling thrust regulation and over-temperature protection control in regenerative cooling engines has the following drawbacks: (1) In the prior art, the fuel used for cooling is ultimately all involved in combustion. After overheating, increasing the flow rate of cooling oil will simultaneously increase the flow rate of combustion oil, directly leading to a passive increase in engine thrust. It is impossible to achieve independent control of cooling and constant thrust, and the two interfere with each other.

[0006] (2) Under the existing overheating treatment method, the increase in thrust will increase the engine flight speed, which in turn will lead to an increase in engine intake air volume, an increase in intake air temperature, an increase in combustion intensity, and a further increase in component heat load, which will aggravate the overheating phenomenon, forming a vicious cycle of positive feedback, which seriously threatens the engine's operational safety.

[0007] (3) The existing technology adopts the method of increasing the total fuel flow rate as a whole, which cannot accurately cool the local overheated area of ​​the combustion chamber. It is easy to have local temperatures still exceed the standard, while the non-overheated area is overcooled. The cooling resources are not allocated reasonably, and it is impossible to allocate them on demand, resulting in low cooling efficiency. Summary of the Invention

[0008] One object of the present invention is to solve at least the above-mentioned problems and / or defects, and to provide at least the advantages described below.

[0009] To achieve these objectives and other advantages of the present invention, a decoupled control method for thrust regulation and overheating treatment of a regenerative cooling engine is provided, comprising: Step 1: Structural improvements are made to the regenerative cooling ramjet engine so that the fuel inlet manifold has multiple independent and symmetrical cooling fuel supply zones, and each cooling fuel supply zone has a supply branch that can independently adjust the fuel supply flow. Temperature sensors are installed in the isolation section-combustion chamber cooling area of ​​each cooling fuel supply zone near the outlet manifold. Step two: After the engine starts, the controller presets reference parameters, including: safe temperature thresholds for each cooling oil supply zone. T i,lim Total fuel supply reference flow rate of fuel pump Q total,ref ; Step 3: During engine operation, the over-temperature decoupling control module of the controller obtains the real-time temperature value of the corresponding cooling oil supply zone through the temperature sensor, and determines whether to adjust the flow rate of each cooling oil supply zone accordingly by over-temperature judgment. Step 4: Once the temperature of all cooling oil supply zones is within a safe range, the over-temperature decoupling control module controls each supply branch to perform balanced oil supply while maintaining a constant total flow rate, so as to maintain the stable operation of the target thrust. Among them, the over-temperature decoupling control follows the principle of constant total flow control when adjusting the flow of each cooling oil supply zone.

[0010] Preferably, in step one, each of the supply branches is equipped with a corresponding regulating valve.

[0011] Preferably, in step two, in the initial state, while ensuring that the total flow rate and the total output flow rate of the fuel pump are consistent, the fuel flow rate of each supply branch is evenly distributed so that the engine thrust is stabilized at the target value and the temperature of each zone is within a safe range.

[0012] Preferably, in step three, the real-time temperature value is obtained by filtering, denoising, and converting the received temperature signal through the over-temperature decoupling control module.

[0013] Preferably, in step four, the flow rate of each cooling oil supply zone is adjusted accordingly as follows: If the real-time temperature value of any cooling oil supply zone T i All are less than or equal to the corresponding safe temperature threshold. T i,lim Then the fuel flow rate of the corresponding supply branch will remain at the initial flow rate; Otherwise, if the corresponding cooling oil supply zone is determined to be overheated, the controller will generate a control command according to the predetermined control strategy, dynamically fine-tune the opening of the flow regulating valve of the overheated cooling oil supply zone to increase the supply of cooling medium; at the same time, based on the principle of constant total flow control, the controller will dynamically fine-tune the opening of the flow regulating valve of other cooling oil supply zones to reduce the supply of cooling medium.

[0014] Preferably, the dynamic fine-tuning is implemented using the following formula: In the above formula, Q i (k+1) represents the fine-tuning control value of the flow regulating valve at the next moment; T i (k) represents the real-time temperature of the i-th cooling oil supply zone at the current moment; Under the principle of constant total flow control ,in, Q i For the flow of each supply branch, and , α For over-temperature treatment flow coefficient, Q i,re This represents the initial fuel flow rate for each branch channel.

[0015] A decoupled control system, comprising: An inlet manifold ring that works in conjunction with the output side of the fuel pump has multiple independent and symmetrically structured cooling and fuel supply zones evenly divided circumferentially inside the inlet manifold ring, thereby forming a fuel-free crossflow in space and multiple cooling channels corresponding to the independent cooling areas of the isolation section and combustion chamber. A supply branch located on the fuel pump output side, used to supply cooling fuel to each cooling channel; Flow regulating valves installed on each supply branch; A temperature sensor that works in conjunction with the corresponding cooling fuel supply zone and is located in the isolation section-combustion chamber cooling area and near the outlet manifold. A controller that communicates with temperature sensors and flow control valves.

[0016] The present invention has at least the following beneficial effects: Firstly, this invention can decouple thrust and overheating control. That is, by independently adjusting the flow rate in different zones and controlling the total flow rate constantly, this invention breaks the coupling relationship between cooling flow rate and combustion flow rate (thrust). Overheating only adjusts the local fuel distribution without changing the fuel supply. The engine thrust always maintains the target value, thus eliminating the vicious cycle of "overheating fueling - increased thrust - increased speed - more overheating" from the root and greatly improving the engine's operational stability and safety.

[0017] Secondly, this invention can achieve precise handling of local overheating and significantly improve cooling efficiency. Specifically, it adopts a 4-zone independent cooling design, which can increase the cooling flow rate for local overheating areas of the engine, so that the cooling oil can be allocated on demand, avoiding the waste of resources in overall flow adjustment and improving the efficiency of overheating handling.

[0018] Third, the system of the present invention requires minimal modification and is highly adaptable. In practical applications, there is no need to modify the core structure of the engine. Only the manifold and fuel line need to be modified in sections, and a regulating valve and temperature sensor need to be added. It is compatible with various existing regenerative cooling engines, has low modification difficulty, strong versatility, and is easy to apply in engineering.

[0019] Fourth, this invention can optimize fuel utilization efficiency and improve engine performance indicators. That is, this technical solution avoids unnecessary increases in total flow, reduces fuel pump power consumption, and supplies cooling oil only in the over-temperature range as needed, thereby improving the utilization efficiency of fuel cooling resources, reducing engine fuel consumption, and improving engine performance indicators.

[0020] Other advantages, objectives and features of the present invention will be apparent in part from the following description, and in part from the understanding of those skilled in the art through study and practice of the invention. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the decoupling control system of the present invention; Among them, 1-fuel tank, 2-electric fuel pump, 3-check valve, 4-flow meter, 5-flow regulating valve I, 6-flow regulating valve II, 7-flow regulating valve III, 8-flow regulating valve VI, 9-segmented inlet manifold, 10-cooling fuel supply zone I, 11-cooling fuel supply zone II, 12-cooling fuel supply zone III, 13-cooling fuel supply zone VI, 14-outlet manifold, 15-temperature sensor I, 16-temperature sensor II, 17-temperature sensor III, 18-temperature sensor VI, 19-high temperature shut-off valve, 20-fuel injector, 21-temperature sensor, 22-controller. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0023] A decoupled control system, based on the existing structure of a regenerative cooled ramjet engine, makes targeted improvements only to the fuel inlet manifold, fuel delivery pipeline, and monitoring and control components, without altering the main engine structure, fuel pump, or combustion components. Figure 1 As shown, the improved system hardware includes: an electric fuel pump 2 that works with the fuel tank 1, a one-way valve 3, a flow meter 4, a segmented inlet manifold ring 9, a multi-way fuel branch channel, a flow regulating valve, a zone temperature sensor, an outlet manifold 14, a high-temperature shut-off valve 19, a fuel injector 20, a temperature sensor 21, and a controller 22. Specifically, its structural improvements are as follows: 1. Segmented design of fuel inlet manifold: The original integral inlet manifold is evenly divided into 4 independent and symmetrical cooling fuel supply zones along the circumference, namely cooling fuel supply zone I10, cooling fuel supply zone II11, cooling fuel supply zone III12, and cooling fuel supply zone VI13. The cooling channels of the 4 zones are completely isolated, with no fuel crossflow. Each zone corresponds to an independent cooling area in the isolation section-combustion chamber, realizing a circumferential zoned cooling layout.

[0024] 2. Fuel line diversion design: The fuel output from the fuel pump is no longer directly delivered to the inlet manifold, but is diverted into 4 independent fuel branch channels. Each branch channel is connected to one manifold section and supplies cooling fuel to that section separately.

[0025] 3. Detection and Control Component Design: High-precision flow control valves (i.e., flow control valve I5, flow control valve II6, flow control valve III7, and flow control valve VI8) are installed on each fuel branch channel to independently regulate the fuel flow of that branch. Fuel temperature sensors (i.e., temperature sensor I15, temperature sensor II16, temperature sensor III17, and temperature sensor VI18) are installed near the outlet manifold in the isolation section of the four segmented manifolds to monitor the fuel temperature of that zone in real time. All flow control valves and temperature sensors are connected to the controller, which receives temperature signals and issues flow control valve control commands.

[0026] A decoupled control method for thrust regulation and over-temperature treatment in a regenerative cooling engine, the control mode including: Step 1: System Initialization and Baseline Parameter Setting After the engine starts, the fuel pump outputs high-pressure, room-temperature fuel, which is then distributed to four fuel branch channels. The controller is pre-set with two sets of core reference parameters: one is the safe temperature threshold for each zone of the combustion chamber. T i,lim (i=1,2,3,4), i.e., the fuel temperature at which the engine is operating normally; and secondly, the reference flow rate of the total fuel supply to the fuel pump. Q total,ref This flow rate, precisely matched to the engine's target thrust, is a core parameter for meeting thrust requirements. Initially, the fuel flow rate in the four branch channels... Q i,ref The flow rate is evenly distributed, and the total flow rate is consistent with the total output flow rate of the fuel pump. The engine thrust is stable at the target value, and the temperature of each zone is within a safe range. T i ≤ T i,lim .

[0027] Step 2: Real-time monitoring of zoned temperatures During engine operation, temperature sensors in four zones continuously collect temperature signals for their respective zones in real time. T i,raw The system transmits the temperature signal to the controller in real time; the controller filters, reduces noise, and converts the temperature signal to obtain accurate real-time temperature values ​​for each zone. T i =Filter( T i,raw ).

[0028] Step 3: Over-temperature detection and single-channel flow regulation 1. The controller compares the real-time temperature of each zone with the preset safe temperature threshold. If the real-time temperature of the partition corresponding to a certain branch channel Ti ≤Safe temperature threshold T i,lim If the zone is determined to be functioning normally, the controller will maintain the opening of the flow regulating valve for that zone unchanged, and the fuel flow will remain at its initial value. Q i = Q i,ref ; If the real-time temperature of the zone corresponding to a certain branch flow channel T i >Safe temperature threshold T i,lim If an overheating condition is detected in a specific zone, the controller generates a flow control valve control command according to a predetermined strategy. This command increases the opening of the flow control valve corresponding to the overheated zone, thereby increasing the flow rate of cooling fuel in that path. By increasing the supply of cooling medium, convective heat transfer in the overheated area is enhanced, achieving targeted cooling. In the formula, α The flow coefficient for over-temperature treatment is related to engine operating characteristics and was obtained from ground tests. Q i,re This represents the initial fuel flow rate for each branch channel.

[0029] 2. Constant total flow control to achieve decoupling This step primarily achieves decoupling of thrust control and overheat handling by adjusting the flow distribution to increase cooling flow in the overheat zone and decrease flow in the non-overheat zone. Specifically, while increasing fuel flow in the overheat zone, the controller simultaneously adjusts the flow control valves in the other three non-overheat zones in the opposite direction, correspondingly reducing their fuel flow. The controller also controls the fuel pump to ensure that the total output flow of the fuel pump remains constant at its initial reference value. 3. Closed-loop stability regulation The controller continuously executes a closed-loop operation of "temperature acquisition - over-temperature judgment - flow regulation". Based on the temperature drop in the over-temperature zone, the opening of the corresponding flow regulating valve is dynamically fine-tuned according to the following formula: If multiple zones experience overheating simultaneously, the controller adjusts the flow regulating valve opening according to the magnitude of the overheating to regulate the cooling flow as needed; at the same time, it controls the fuel pump to ensure a constant total fuel flow until the temperature of all zones returns to the safe threshold range, thus completing the overheating handling.

[0030] 4. Maintaining normal operating conditions Once all zone temperatures are within safe limits, the controller restores each flow regulating valve to its initial opening, thus restoring the flow rate of each branch zone to its initial value.Q i,ref Continue to maintain total traffic. Q total,ref The engine maintains a constant target thrust.

[0031] The above solution is merely an illustration of a preferred example and is not limited thereto. When implementing this invention, appropriate substitutions and / or modifications can be made according to the user's needs.

[0032] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. It can be applied to various fields suitable for the present invention. Other modifications can be readily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and examples shown and described herein.

Claims

1. A decoupled control method for thrust regulation and overheat treatment in a regenerative cooling engine, characterized in that, include: Step 1: Structural improvements are made to the regenerative cooling ramjet engine so that the fuel inlet manifold has multiple independent and symmetrical cooling fuel supply zones, and each cooling fuel supply zone has a supply branch that can independently adjust the fuel supply flow. Temperature sensors are installed in the isolation section-combustion chamber cooling area of ​​each cooling fuel supply zone near the outlet manifold. Step two: After the engine starts, the controller presets reference parameters, including: safe temperature thresholds for each cooling oil supply zone. T i,lim Total fuel supply reference flow rate of fuel pump Q total,ref ; Step 3: During engine operation, the over-temperature decoupling control module of the controller obtains the real-time temperature value of the corresponding cooling oil supply zone through the temperature sensor, and determines whether to adjust the flow rate of each cooling oil supply zone accordingly by over-temperature judgment. Step 4: Once the temperature of all cooling oil supply zones is within a safe range, the over-temperature decoupling control module controls each supply branch to perform balanced oil supply while maintaining a constant total flow rate, so as to maintain the stable operation of the target thrust. Among them, the over-temperature decoupling control follows the principle of constant total flow control when adjusting the flow of each cooling oil supply zone.

2. The decoupling control method for thrust regulation and overheat treatment of a regenerative cooling engine as described in claim 1, characterized in that, In step one, each of the supply branches is equipped with a corresponding regulating valve.

3. The decoupling control method for thrust regulation and over-temperature treatment of a regenerative cooling engine as described in claim 1, characterized in that, In step two, in the initial state, while ensuring that the total flow rate and the total output flow rate of the fuel pump are consistent, the fuel flow rate of each supply branch is evenly distributed so that the engine thrust is stabilized at the target value and the temperature of each zone is within a safe range.

4. The decoupled control method for thrust regulation and over-temperature treatment of regenerative cooling engine as described in claim 1, characterized in that, In step three, the real-time temperature value is obtained by filtering, denoising, and converting the received temperature signal through the over-temperature decoupling control module.

5. The decoupled control method for thrust regulation and overheat treatment of a regenerative cooling engine as described in claim 1, characterized in that, In step four, the flow rate of each cooling oil supply zone is adjusted accordingly as follows: If the real-time temperature value of any cooling oil supply zone T i All are less than or equal to the corresponding safe temperature threshold. T i,lim Then the fuel flow rate of the corresponding supply branch will remain at the initial flow rate; Otherwise, if the corresponding cooling oil supply zone is determined to be overheated, the controller will generate a control command according to the predetermined control strategy, dynamically fine-tune the opening of the flow regulating valve of the overheated cooling oil supply zone to increase the supply of cooling medium; at the same time, based on the principle of constant total flow control, the controller will dynamically fine-tune the opening of the flow regulating valve of other cooling oil supply zones to reduce the supply of cooling medium.

6. The decoupled control method for thrust regulation and overheat treatment of a regenerative cooling engine as described in claim 5, characterized in that, The dynamic fine-tuning is achieved using the following formula: In the above formula, Q i (k+1) represents the fine-tuning control value of the flow regulating valve at the next moment; T i (k) represents the real-time temperature of the i-th cooling oil supply zone at the current moment; Under the principle of constant total flow control ,in, Q i For the flow of each supply branch, and , α For over-temperature treatment flow coefficient, Q i,re This represents the initial fuel flow rate for each branch channel.

7. A decoupling control system, applied in the decoupling control method for thrust regulation and overheat treatment of a regenerative cooling engine as described in any one of claims 1-6, characterized in that, include: An inlet manifold ring that works in conjunction with the output side of the fuel pump has multiple independent and symmetrically structured cooling and fuel supply zones evenly divided circumferentially inside the inlet manifold ring, thereby forming a fuel-free crossflow in space and multiple cooling channels corresponding to the independent cooling areas of the isolation section and combustion chamber. A supply branch located on the fuel pump output side, used to supply cooling fuel to each cooling channel; Flow regulating valves installed on each supply branch; A temperature sensor that works in conjunction with the corresponding cooling fuel supply zone and is located in the isolation section-combustion chamber cooling area and near the outlet manifold. A controller that communicates with temperature sensors and flow control valves.

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