Ammonia fuel based combustion chamber in-situ injection regenerative cooling system and control method

Abstract

This application provides an in-situ injection regeneration cooling system for ammonia-fueled combustion chambers, including a combustion chamber, a fuel supply assembly, and a control module. The combustion chamber includes a flame tube and a cooling channel. The fuel supply assembly includes a liquid ammonia storage tank, a direct injection pipeline, and a regeneration cooling pipeline. The direct injection pipeline is connected to the nozzle of the flame tube, and the regeneration cooling pipeline is connected to the cooling channel. The cooling channel is connected to the flame tube. A first flow regulating device is installed on the direct injection pipeline, and a second flow regulating device is installed on the regeneration cooling pipeline. A temperature monitoring device is installed in the area with the highest heat load in the cooling channel. The control method is that the control module adjusts the second flow regulating device according to the temperature obtained by the temperature monitoring device to regulate the cooling flow rate into the cooling channel. The control module calculates the difference between the total fuel flow rate and the cooling flow rate entering the flame tube according to the set total fuel flow rate and cooling flow rate, and controls the first flow regulating device according to the difference to regulate the injection flow rate into the flame tube.

Description

Technical Field

[0001] This application relates to the field of aero-engine technology, and in particular to an in-situ injection regeneration cooling system and control method for ammonia fuel-based combustion chambers. Background Technology

[0002] As aerospace vehicles continue to evolve towards higher Mach numbers and higher thrust-to-weight ratios, engine turbine inlet temperatures and combustion chamber heat flux densities are rising dramatically. Faced with such severe thermal loads, traditional combustion chamber thermal protection largely relies on film cooling technology. However, this technology consumes some high-quality compressed air, leading to a reduction in engine effective thrust and cycle thermal efficiency. Therefore, active regenerative cooling technology, which uses the fuel itself as a cooling medium, can reduce cooling air consumption and increase engine thrust, aligning with the future development trend of high-thrust aero-engines.

[0003] Existing regenerative cooling technologies mostly use traditional hydrocarbon fuels such as aviation kerosene, which have relatively low physical heat sink limits. Under high heat load conditions, hydrocarbon fuels are prone to large molecular bond breaking, resulting in coking and carbon buildup, which blocks micro-cooling channels and ultimately leads to the failure of thermal protection systems. In contrast, liquid ammonia, as a highly promising carbon-free fuel, has a significantly higher heat sink than aviation kerosene, can withstand higher heat loads, and fundamentally eliminates the risk of high-temperature coking and blockage. Furthermore, ammonia is a zero-carbon clean energy source, aligning with the global aviation propulsion sector's requirements for carbon emission control and green development.

[0004] Despite the significant advantages of liquid ammonia in terms of thermal protection and zero carbon emissions, its use as a primary fuel for aero engines still faces challenges. Ammonia's laminar flame velocity is approximately 7 cm / s, only about one-fifth that of conventional methane, and its minimum ignition energy is relatively high. If liquid ammonia is directly injected into the combustion chamber, its intense vaporization and heat absorption can lead to a sharp drop in localized temperatures, easily causing problems such as ignition difficulties, unstable combustion, and low overall combustion efficiency. However, allowing liquid ammonia to absorb waste heat from the combustion chamber during regeneration and cooling can not only significantly increase its initial temperature and reduce the apparent activation energy of combustion, but also utilize the heat released by the initial combustion of some ammonia gas to provide a more favorable environment for subsequent combustion.

[0005] The aforementioned liquid ammonia cooling technology still faces bottlenecks in engineering implementation. In traditional regenerative cooling systems, the cooling medium, after absorbing heat, typically needs to be guided to the combustion chamber nozzles via a complex external manifold. This external manifold distribution structure not only increases the engine's structural weight and flow resistance but also easily leads to uneven two-phase flow distribution. Simultaneously, the high heat load cooling requirements of the combustion chamber walls and the fuel supply requirements for a stable air-fuel ratio in the main combustion zone must be dynamically balanced through appropriate control strategies.

[0006] Therefore, there is an urgent need in this field for a novel ammonia fuel regeneration cooling and control system with a simplified structure that can achieve dynamic synergy between cooling and combustion support. Summary of the Invention

[0007] To address the technical problems of insufficient thermal protection capabilities of existing engines and the difficulty in igniting and stabilizing ammonia fuel combustion, this invention proposes an in-situ injection regenerative cooling system and control method for the combustion chamber based on ammonia fuel. This system deeply integrates ammonia fuel regenerative cooling with in-situ injection, enhancing the thermal protection of the combustion chamber and improving the combustion activity of ammonia fuel while reducing the consumption of compressed air by film cooling, thereby improving the overall thermal efficiency and thrust of the engine.

[0008] To solve the above-mentioned technical problems, this application provides an in-situ injection regeneration cooling system for combustion chambers based on ammonia fuel, adopting the following technical solution:

[0009] It includes a combustion chamber, a fuel supply assembly, and a control module; the combustion chamber includes a flame tube and a cooling channel surrounding the outside of the flame tube; the fuel supply assembly includes a liquid ammonia storage tank and a direct injection pipeline and a regeneration cooling pipeline leading out from the liquid ammonia storage tank;

[0010] The direct injection pipeline is connected to the nozzle of the flame tube, and the regeneration cooling pipeline is connected to the cooling channel; the cooling channel is connected to the flame tube; a first flow regulating device is provided on the direct injection pipeline, and a second flow regulating device is provided on the regeneration cooling pipeline.

[0011] A temperature monitoring device is installed in the cooling channel in the area with the highest heat load. The temperature monitoring device, the first flow regulating device, and the second flow regulating device are respectively electrically connected to the control module. The control module adjusts the second flow regulating device according to the temperature monitored by the temperature monitoring device to regulate the cooling flow rate into the cooling channel. The control module calculates the difference between the total fuel flow rate and the cooling flow rate into the flame tube according to the set total fuel flow rate and cooling flow rate, and controls the first flow regulating device according to the difference to regulate the injection flow rate into the flame tube.

[0012] In a preferred embodiment: a first flow meter is installed on the direct injection pipeline for real-time measurement of the injection flow rate in the direct injection pipeline; a second flow meter is installed on the regeneration cooling pipeline for real-time measurement of the cooling flow rate in the regeneration cooling pipeline; the first flow meter and the second flow meter are respectively electrically connected to the control module.

[0013] In a preferred embodiment: a first pressure regulating component is provided on the direct injection pipeline, and a second pressure regulating component is provided on the regeneration cooling pipeline; the first pressure regulating component and the second pressure regulating component are respectively controlled by the control module.

[0014] When the flow rate opening of the first flow regulating device or the second flow regulating device changes, it causes a local pressure change in the direct injection pipeline or regeneration cooling pipeline, and the first pressure regulating component or the second pressure regulating component performs pressure compensation respectively.

[0015] In a preferred embodiment: the first pressure regulating component includes a first variable frequency high-pressure pump and a first pressure sensor; the second pressure regulating component includes a second variable frequency high-pressure pump and a second pressure sensor; both the first flow regulating device and the second flow regulating device are electric regulating valves.

[0016] In a preferred embodiment: the cooling channel is provided with an in-situ direct-injection nozzle at one end connected to the flame tube, and the cooling flow, after absorbing heat, is directly injected into the interior of the flame tube in the form of a transverse jet through the in-situ direct-injection nozzle.

[0017] In a preferred embodiment: the cooling channel has a built-in first temperature sensor and a second temperature sensor, the second temperature sensor being the temperature monitoring device, and the first temperature sensor being electrically connected to the control module;

[0018] The first temperature sensor is arranged on the inlet side of the in-situ direct-injection nozzle and is located upstream of the in-situ direct-injection nozzle along the fluid flow direction; the first temperature sensor is used to monitor the temperature of the cooling flow rate after heat absorption and to determine whether the superheated vaporization state has been reached.

[0019] In a preferred embodiment: a plurality of first temperature sensors are arranged circumferentially at the inlet side of the in-situ direct-fire nozzle; a plurality of second temperature sensors are arranged circumferentially at the area of ​​maximum heat load in the cooling channel.

[0020] In a preferred embodiment: the cooling channel is provided with several turbulence columns and several ribs, and the turbulence columns are teardrop-shaped turbulence columns;

[0021] A sleeve structure is provided inside the cooling channel. The sleeve structure is a hollow cylinder. The sleeve structure is horizontally arranged in the cooling channel to connect the flame tube with the external space of the cooling channel, forming an air channel that runs through the cooling channel.

[0022] In a preferred embodiment: the cooling channel adopts a counter-flow cooling path layout; the connection end of the cooling channel and the regenerative cooling pipeline is located at the tail end of the combustion chamber, and the connection end of the cooling channel and the flame tube is located at the head end of the combustion chamber.

[0023] To address the aforementioned technical problems, this application provides a control method for an in-situ injection regeneration cooling system for ammonia fuel combustion chamber, employing the following technical solution:

[0024] Based on the aforementioned ammonia-fuel-based in-situ injection regeneration cooling system for combustion chambers, the control method is as follows:

[0025] The control module will monitor the temperature T at the area of ​​maximum heat load, which is collected in real time by the temperature monitoring device. h and the safe temperature threshold T set within the control module. set Perform a difference comparison; if T h Higher than T set At that time, the PID algorithm module built into the control module calculates the target cooling flow rate Q required to eliminate the temperature difference based on the rate of change and cumulative amount of the temperature deviation. c-t Perform flow rate calculation to obtain the actual cooling flow rate Q in the regeneration cooling pipeline. c The target cooling flow rate Q is calculated and output. c-t Perform comparison calculations to generate action commands to drive the adjustment opening of the second flow regulating device;

[0026] While performing cooling flow regulation, the control module adjusts the total fuel flow rate Q set within the control module. t Using formula Q f-t =Q t -Q c The calculated target flow rate Q that the nozzle of the flame tube should currently possess f-t The actual cooling flow rate Q in the direct-connected injection pipeline f The target cooling flow rate Q is calculated and output. f-t A comparison calculation is performed to generate an action command to drive the adjustment opening of the first flow regulating device.

[0027] In summary, this application has the following beneficial effects:

[0028] 1. Significantly improves the thermal protection capability of the combustion chamber and solves the problem of excessive heat load on the combustion chamber wall: This invention utilizes the huge heat sink formed by the physical sensible heat and latent heat of vaporization of liquid ammonia fuel itself. Liquid ammonia is used as a cooling medium and introduced into a cooling channel surrounding the outside of the flame tube to directly regenerate and cool the combustion chamber flame tube, which can efficiently remove a large amount of heat from the flame tube wall. At the same time, the temperature monitoring device set in the area of ​​maximum heat load in the cooling channel can provide real-time feedback on the wall temperature. The control module uses this information to precisely adjust the second flow regulating device and dynamically adapt the cooling flow rate to ensure stable and reliable cooling effect in the area of ​​maximum heat load. This completely solves the technical problem of insufficient thermal protection of the combustion chamber wall in existing aero-engines, effectively extends the service life of the combustion chamber, and improves the operational safety of the system.

[0029] 2. Optimize ammonia fuel combustion performance and achieve stable combustion across a wide boundary: This invention introduces liquid ammonia into the cooling channel through a regenerative cooling pipeline. After the liquid ammonia absorbs heat and vaporizes in the channel, it is injected directly into the flame tube from the connection between the cooling channel and the flame tube without the need for an external collection device, and combusts together with the fuel injected through the direct injection pipeline. The high-temperature ammonia gas generated by in-situ vaporization effectively improves the combustion activity of ammonia fuel, solves the problems of difficult ignition and unstable combustion of ammonia fuel, achieves stable combustion of ammonia fuel across a wide boundary, and avoids performance loss caused by incomplete combustion of ammonia fuel.

[0030] 3. Reduce energy consumption and improve overall engine thermal efficiency and thrust: This invention integrates the cooling function of ammonia fuel with the fuel supply function, eliminating the need for additional cooling medium and delivery system. Furthermore, by replacing traditional film cooling with regenerative cooling, it reduces compressed air consumption and lowers engine energy losses. In addition, the control module, through temperature monitoring signals and total fuel flow setpoints, coordinates the first and second flow regulation devices to precisely match the cooling flow and injection flow, ensuring maximum fuel utilization efficiency and effectively improving the engine's overall thermal efficiency and thrust performance.

[0031] 4. Green and environmentally friendly, reducing carbon emissions: This invention uses ammonia fuel as both the cooling medium and the combustion fuel. Ammonia fuel produces no carbon emissions during combustion. Compared to traditional fossil fuels, it can significantly reduce carbon emissions during engine operation, meeting the green and low-carbon development needs of the aviation industry and providing excellent environmental benefits.

[0032] 5. The system is precise and reliable with strong adaptability: The control module realizes the telematic linkage between the temperature monitoring device, the first flow regulating device, and the second flow regulating device. It can collect the temperature signal of the area with the maximum heat load in the cooling channel in real time, dynamically regulate the cooling flow, and precisely adjust the injection flow according to the difference between the total fuel flow and the cooling flow, so as to ensure that the system operating parameters are always in the optimal state, adapt to the engine operating requirements under different working conditions, and improve the stability and adaptability of the system. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of the combustion chamber in-situ injection regeneration cooling system based on ammonia fuel in this embodiment.

[0034] Figure 2 This is an axial cross-sectional schematic diagram of the in-situ injection regeneration cooling channel in the combustion chamber of this embodiment;

[0035] Figure 3 This is a radial cross-sectional schematic diagram of the combustion chamber flame tube and cooling channel in this embodiment.

[0036] Explanation of reference numerals in the attached drawings: 1. Liquid ammonia storage tank; 2. First variable frequency high-pressure pump; 3. First pressure sensor; 4. First electric regulating valve; 5. First flow meter; 6. Second variable frequency high-pressure pump; 7. Second pressure sensor; 8. Second electric regulating valve; 9. Second flow meter; 10. Check valve; 11. First temperature sensor; 12. Second temperature sensor; 13. Combustion chamber; 14. Central control unit; 15. In-situ direct-injection nozzle; 16. Teardrop-shaped turbulence column; 17. Sleeve structure; 18. Outer casing; 19. Cooling channel outer wall; 20. Rib; 21. Flame tube outer wall; 22. Flame tube front end nozzle; 23. Flame tube inner wall; 24. Inner casing. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0038] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0039] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed", "equipped", "sleeved / connected", "connected", etc., should be interpreted broadly. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0040] The following is in conjunction with the appendix Figures 1-3 This application will be described in further detail.

[0041] This application proposes an in-situ injection regenerative cooling system and control method for ammonia fuel in the combustion chamber, aiming to solve problems such as insufficient thermal protection of the engine wall, thrust reduction due to traditional film cooling crowding out combustion air, and low reactivity and ignition difficulty of zero-carbon ammonia fuel. The system and control method utilize the zero-coking, high sensible heat, and high latent heat of vaporization of liquid ammonia to construct an efficient heat sink, reducing cooling air consumption and increasing engine thrust. Simultaneously, the ammonia fuel is preheated and vaporized using waste heat from the combustion chamber 13 before in-situ direct injection, improving combustion activity and simplifying the flow distribution structure. Through these synergistic effects, stable combustion of ammonia fuel is promoted, achieving a comprehensive improvement in both thermal protection and combustion performance.

[0042] Specifically, the ammonia-fuel-based in-situ injection and regeneration cooling system for combustion chambers includes a combustion chamber 13, a fuel supply assembly, and a control module. The combustion chamber 13 includes a flame tube and a cooling channel surrounding the outside of the flame tube. The fuel supply assembly includes a liquid ammonia storage tank 1 and a direct injection pipeline and a regeneration cooling pipeline extending from the liquid ammonia storage tank 1. The direct injection pipeline is connected to the nozzle of the flame tube, and the regeneration cooling pipeline is connected to the cooling channel. The cooling channel is connected to the flame tube. A first flow rate regulating device is installed on the direct injection pipeline, and a second flow rate regulating device is installed on the regeneration cooling pipeline. The cooling channel includes a temperature monitoring device located in the area of ​​maximum heat load. The temperature monitoring device, the first flow regulating device, and the second flow regulating device are electrically connected to the control module. The control module adjusts the second flow regulating device based on the temperature monitored by the temperature monitoring device to regulate the cooling flow rate entering the cooling channel. The control module calculates the difference between the total fuel flow rate and the cooling flow rate entering the flame tube based on the set total fuel flow rate and cooling flow rate, and controls the first flow regulating device based on the difference to regulate the injection flow rate entering the flame tube.

[0043] The combustion chamber 13 has the following specific structure: it includes an outer casing 18, an outer wall of a cooling channel 19, an outer wall of a flame tube 21, an inner wall of a flame tube 23, a flame tube front nozzle and an inner casing 24, as well as ribs 20, teardrop-shaped baffles 16, a sleeve structure 17 and an in-situ direct-injection nozzle 15 disposed in the cooling channel.

[0044] The combustion chamber 13 is coaxially mounted outside the engine main shaft, located between the compressor outlet and the turbine inlet, and has an overall annular structure. A nozzle is installed on the front end face of the flame tube, and a high-energy igniter is arranged in the recirculation zone at the head of the flame tube. The inner wall 23 and outer wall 21 of the flame tube are coaxially arranged within the combustion chamber 13, forming the main combustion zone. To decouple structural load-bearing and thermal protection functions, the outer wall 21 of the flame tube adopts a double-walled jacket structure, consisting of a cooling channel outer wall 19 and the outer wall 21 of the flame tube. The cooling channel outer wall 19 is located on the side furthest from the flame, serving as a load-bearing frame and primarily bearing the high-pressure air load between the outer casing 18 and the cooling channel outer wall 19. The outer wall 21 of the flame tube acts on the side directly in contact with the combustion flame, bearing the thermal load from combustion.

[0045] A regenerative cooling channel is formed between the outer wall 21 of the flame tube and the outer wall 19 of the cooling channel. In this embodiment, the cooling channel adopts a counter-current cooling flow path layout. The connection end of the cooling channel and the regenerative cooling pipeline is located at the tail of the combustion chamber 13, and the connection end of the cooling channel and the flame tube is located at the head of the combustion chamber 13. The inlet of the liquid ammonia cooling medium is located at the tail of the combustion chamber 13, and the outlet is close to the head. The liquid ammonia flows from back to front in the cooling channel, forming a counter-current heat exchange with the high-temperature gas flowing from front to back in the combustion chamber 13, maintaining a large heat transfer temperature difference along the entire length of the flow channel.

[0046] By incorporating several teardrop-shaped turbulence columns 16 and several fins 20 within the cooling channel, with the fins 20 positioned between the outer wall 19 of the cooling channel and the inner wall 23 of the flame tube, the liquid ammonia cooling medium experiences increased heat exchange time as it passes through the teardrop-shaped turbulence columns 16 in the regeneration cooling channel. Furthermore, the fins 20 increase the heat exchange area between the liquid ammonia cooling medium and the turbulence column 16. This design, by extending the residence time and heat exchange area of ​​the liquid ammonia cooling medium within the cooling channel through the teardrop-shaped turbulence columns 16, not only utilizes the heat sink of ammonia to powerfully cool the flame tube wall but also improves heat exchange efficiency. Moreover, the streamlined teardrop shape prevents the formation of a slow-flowing dead zone behind the turbulence columns. The fins 20 further increase the heat exchange area, causing the fluid temperature to gradually increase along the flow direction.

[0047] The cooling channel is connected to one end of the flame tube and is equipped with an in-situ direct-injection nozzle 15. After absorbing heat, the cooling flow rate is directly injected into the interior of the flame tube in the form of a transverse jet through the in-situ direct-injection nozzle 15.

[0048] After absorbing heat, the liquid ammonia cooling medium is directly injected into the combustion chamber 13 at the end of the cooling channel via the in-situ direct-injection nozzle 15 in the form of a transverse jet. The injected ammonia not only improves combustion performance due to the increased temperature, but also enhances the flow field disturbance in the main combustion zone due to the jet, thereby improving mixing. The in-situ direct-injection nozzle 15 also functions as a back pressure valve here, preventing the backflow of high-temperature combustion gas into the combustion chamber 13 and ensuring that the cooling medium in the cooling channel does not boil rapidly due to sudden pressure changes.

[0049] A sleeve structure 17 is provided inside the cooling channel. The sleeve structure 17 is a hollow cylinder. The sleeve structure 17 is horizontally arranged in the cooling channel to connect the flame tube with the external space of the cooling channel, forming an air channel that runs through the cooling channel.

[0050] The sleeve structure 17 is used to form a dedicated flow channel for avoidance and isolation. Specifically, it is a thin-walled hollow cylinder with its two ends connected to the openings on the outer wall 19 of the cooling channel and the outer wall 21 of the flame tube, respectively, thus forming an air channel that penetrates the double-walled structure. The liquid ammonia fluid in the cooling channel is blocked by the sleeve structure 17, forming a flow around the sleeve, and then converging behind the sleeve. This structure effectively achieves physical isolation between the high-pressure air flow channel and the high-pressure liquid ammonia flow channel, preventing mutual leakage and mixing of the working fluid and ensuring the safety of the system.

[0051] The specific structure of the fuel supply assembly is as follows: a direct injection pipeline and a regeneration cooling pipeline are led out from the liquid ammonia storage tank 1. One of the direct injection pipelines is connected in series with a first variable frequency high-pressure pump 2, a first pressure sensor 3, a first electric regulating valve 4 and a first flow meter 5, and its end is connected to the nozzle 22 at the front end of the flame tube. The other regeneration cooling pipeline is connected in series with a second variable frequency high-pressure pump 6, a second pressure sensor 7, a second electric regulating valve 8, a second flow meter 9 and a one-way valve 10, and its end is connected to the inlet end of the cooling channel.

[0052] Both the first flow regulating device and the second flow regulating device are electric regulating valves. The first flow meter 5 is used to measure the injection flow rate in the direct-connected injection pipeline in real time. The second flow meter 9 is used to measure the cooling flow rate in the regeneration cooling pipeline in real time. The first flow meter 5 and the second flow meter 9 are respectively electrically connected to the control module.

[0053] The first variable frequency high-pressure pump 2 and the first pressure sensor constitute the first pressure regulating component, and the second variable frequency high-pressure pump 6 and the second pressure sensor 7 constitute the second pressure regulating component. The first pressure regulating component and the second pressure regulating component are respectively controlled by the control module. When the flow opening of the first flow regulating device or the second flow regulating device changes, it causes a local pressure change in the direct injection pipeline or regeneration cooling pipeline, and the first pressure regulating component or the second pressure regulating component respectively performs pressure compensation.

[0054] The cooling channel is equipped with a first temperature sensor 11 and a second temperature sensor 12. The second temperature sensor 12 is the temperature monitoring device, and the first temperature sensor 11 is electrically connected to the control module. The first temperature sensor 11 is arranged on the inlet side of the in-situ direct-injection nozzle 15 and is located upstream of the in-situ direct-injection nozzle 15 along the fluid flow direction. The first temperature sensor 11 is used to monitor the temperature of the cooling flow rate after heat absorption and to determine whether it has reached the superheated vaporization state.

[0055] In this configuration, several first temperature sensors 11 are arranged circumferentially at the inlet side of the in-situ direct-injection nozzle 15; several second temperature sensors 12 are arranged circumferentially at the area of ​​maximum heat load in the cooling channel. The signals from the pressure sensors, temperature sensors, and flow meters are synchronously transmitted to the input terminal of the control module. The control module employs a central control unit 14, and its output terminal is connected to the corresponding variable frequency high-pressure pump and electric regulating valve for outputting action commands.

[0056] This embodiment provides a control method for an ammonia-fuel-based combustion chamber in-situ injection regeneration cooling system.

[0057] The control method is as follows:

[0058] The control module will monitor the temperature T at the area of ​​maximum heat load, which is collected in real time by the temperature monitoring device. h and the safe temperature threshold T set within the control module. set Perform a difference comparison; if T h Higher than T set At that time, the PID algorithm module built into the control module calculates the target cooling flow rate Q required to eliminate the temperature difference based on the rate of change and cumulative amount of the temperature deviation. c-t Perform flow rate calculation to obtain the actual cooling flow rate Q in the regeneration cooling pipeline. c The target cooling flow rate Q is calculated and output. c-t Perform comparison calculations to generate action commands to drive the adjustment opening of the second flow regulating device;

[0059] While performing cooling flow regulation, the control module adjusts the total fuel flow rate Q set within the control module. t Using formula Q f-t =Q t -Q c The calculated target flow rate Q that the nozzle of the flame tube should currently possess f-t The actual cooling flow rate Q in the direct-connected injection pipeline f The target cooling flow rate Q is calculated and output. f-t A comparison calculation is performed to generate an action command to drive the adjustment opening of the first flow regulating device.

[0060] Specifically, during continuous engine operation, the system performs high-frequency data acquisition. A second temperature sensor 12, located in the high-heat-load zone of the combustion chamber 13, monitors the heating state of the solid wall surface in real time and extracts the temperature T of the high-heat-load zone. h To determine whether the cooling requirements can be fully met, a first temperature sensor 11, installed in front of the in-situ direct-injection nozzle 15, monitors the temperature T of gaseous ammonia in real time before in-situ injection. n This is to verify whether it has reached the superheated vaporization state. Simultaneously, the first flow meter 5, the second flow meter 9, the first pressure sensor 3, and the second pressure sensor 7 measure the actual mass flow rate Q of liquid ammonia in the direct-connection injection pipeline and the regeneration cooling pipeline in real time, respectively. f Q c And actual pressure P f P c The aforementioned multi-source physical signals are transmitted to the central control unit 14 in real time.

[0061] After receiving the signal, the central control unit 14 executes control logic calculations. First, it performs an outer-loop temperature calculation: the central control unit 14 will use the real-time collected temperature T of the high heat load zone... h With the system's built-in safe temperature threshold T set Perform a difference comparison. When T h Higher than T set At that time, the PID algorithm module built into the central control unit 14 calculates the target cooling flow rate Q required to eliminate the temperature difference based on the rate of change and cumulative amount of the temperature deviation. c-t Then, flow rate calculation is performed, and the actual cooling flow rate Q returned by the second flow meter 9 is calculated. c With the calculated output Q c-t The comparison is performed to generate an action command for driving the second electric regulating valve 8 to meet the flow requirements for cooling.

[0062] To ensure a constant air-fuel ratio in the main combustion zone under variable thrust conditions, the central control unit 14 performs flow distribution calculations simultaneously with cooling flow regulation. The central control unit 14 reads the total ammonia fuel demand Q set under the current engine operating condition command. t And using formula Q f-t =Q t -Q c Calculate the target flow rate Q that the nozzle 22 at the front end of the flame tube should currently possess. f-t This is compared with the actual injection flow rate Q returned by the first flow meter 5. f The comparison calculation is performed, and the action command for the first electric regulating valve 4 is generated accordingly.

[0063] When the first electric regulating valve 4 or the second electric regulating valve 8 changes its opening degree according to the control command, the flow cross-sectional area and fluid resistance in the two independent pipelines change, directly causing local pressure changes in the pipelines. At this time, the first pressure sensor 3 and the second pressure sensor 7 installed in the independent pipelines immediately capture the actual pressure P. f and P c The pressure changes and the pressure fluctuation signal is fed back to the central control unit 14. Since there is a definite correspondence between the pressure, speed and flow rate of the variable frequency high-pressure pump when maintaining a constant system pressure, the central control unit 14 outputs an action command to the first variable frequency high-pressure pump 2 or the second variable frequency high-pressure pump 6 to adjust its speed, thereby completing pressure compensation and maintaining the stability of the system pipeline pressure.

[0064] This invention innovatively proposes to utilize the massive heat sink formed by the physical sensible heat and latent heat of vaporization during the phase change of liquid ammonia for cooling. Compared to the traditional aviation kerosene cooling method that relies solely on physical sensible heat, this solution significantly increases the heat load it can withstand. The cooling channel adopts a fully counter-flow layout, and teardrop-shaped baffles 16 and fins 20 are set within the channel. This not only effectively increases the heat exchange area and extends the heat exchange time, but the teardrop-shaped streamline design also eliminates the slow flow dead zone behind the baffles, avoiding localized heat load concentration, thereby more effectively reducing the wall temperature of the combustion chamber 13 and extending the engine's service life.

[0065] High-temperature ammonia gas, after endothermic vaporization, is directly injected into the combustion chamber 13 in a transverse jet form through the in-situ direct-injection nozzle 15 at the end of the channel. This design eliminates the complex external flow collection and distribution structure of traditional regenerative cooling systems, reducing engine weight. The transverse jet form enhances the flow field disturbance in the main combustion zone, promoting the mixing of ammonia and air; at the same time, the high-temperature gaseous ammonia effectively reduces the reaction activation energy and widens the stable combustion boundary of ammonia fuel. In addition, the in-situ injection orifice at this location also functions as a back pressure valve, effectively preventing the backflow of high-temperature combustion gas into the combustion chamber 13 and suppressing rapid boiling of the cooling medium and two-phase flow oscillation caused by sudden pressure rises and falls within the cooling channel.

[0066] Compared to regenerative cooling systems using traditional hydrocarbon fuels, the ammonia fuel used in this solution contains no carbon, eliminating the risk of cracking, coking, and clogging of cooling channels at high temperatures. This significantly reduces system maintenance costs and improves operational reliability. The sleeve structure 17 proposed in this invention achieves physical isolation between the high-pressure air flow channel and the high-pressure liquid ammonia cooling flow channel, fundamentally preventing mutual leakage and mixing of the two operating media in the double-wall structure, further enhancing system safety. The heat lost from the combustion chamber 13 to the outer wall is fully absorbed by the liquid ammonia fuel and converted into the high-quality enthalpy of ammonia gas. This waste heat, which would otherwise be dissipated, is ultimately recovered into the combustion chamber 13 along with the high-temperature fuel re-injection to perform work, forming a perfect energy recovery cycle, thereby significantly improving the overall thermal efficiency of the engine.

[0067] The above description is merely a preferred embodiment of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention by those skilled in the art within the scope of the technology disclosed in the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. A combustion chamber in-situ injection regeneration cooling system based on ammonia fuel, characterized in that: It includes a combustion chamber, a fuel supply assembly, and a control module; the combustion chamber includes a flame tube and a cooling channel surrounding the outside of the flame tube; the fuel supply assembly includes a liquid ammonia storage tank and a direct injection pipeline and a regeneration cooling pipeline leading out from the liquid ammonia storage tank; The direct injection pipeline is connected to the nozzle of the flame tube, and the regeneration cooling pipeline is connected to the cooling channel; the cooling channel is connected to the flame tube; a first flow regulating device is provided on the direct injection pipeline, and a second flow regulating device is provided on the regeneration cooling pipeline. The cooling channel is equipped with a temperature monitoring device located in the area of ​​maximum heat load. The temperature monitoring device, the first flow regulating device, and the second flow regulating device are respectively electrically connected to the control module. The control module adjusts the second flow regulating device according to the temperature monitored by the temperature monitoring device, so as to regulate the cooling flow into the cooling channel; The control module calculates the difference between the total fuel flow rate and cooling flow rate set for the flame tube, and controls the first flow rate regulating device based on the difference to adjust the injection flow rate into the flame tube.

2. The in-situ injection regeneration cooling system for combustion chambers based on ammonia fuel according to claim 1, characterized in that: A first flow meter is installed on the direct injection pipeline to measure the injection flow rate in the direct injection pipeline in real time; a second flow meter is installed on the regeneration cooling pipeline to measure the cooling flow rate in the regeneration cooling pipeline in real time; the first flow meter and the second flow meter are respectively electrically connected to the control module.

3. The in-situ injection regeneration cooling system for combustion chambers based on ammonia fuel according to claim 1, characterized in that: A first pressure regulating component is provided on the direct injection pipeline, and a second pressure regulating component is provided on the regeneration cooling pipeline. The first pressure regulating component and the second pressure regulating component are respectively controlled by the control module. When the flow rate opening of the first flow regulating device or the second flow regulating device changes, it causes a local pressure change in the direct injection pipeline or regeneration cooling pipeline, and the first pressure regulating component or the second pressure regulating component performs pressure compensation respectively.

4. The in-situ injection regeneration cooling system for combustion chambers based on ammonia fuel according to claim 3, characterized in that: The first pressure regulating component includes a first variable frequency high-pressure pump and a first pressure sensor; the second pressure regulating component includes a second variable frequency high-pressure pump and a second pressure sensor; both the first flow regulating device and the second flow regulating device are electric regulating valves.

5. The in-situ injection regeneration cooling system for combustion chambers based on ammonia fuel according to claim 1, characterized in that: The cooling channel is connected to one end of the flame tube and is equipped with an in-situ direct-injection nozzle. After absorbing heat, the cooling flow rate is directly injected into the interior of the flame tube in the form of a transverse jet through the in-situ direct-injection nozzle.

6. The in-situ injection regeneration cooling system for combustion chambers based on ammonia fuel according to claim 5, characterized in that: The cooling channel is equipped with a first temperature sensor and a second temperature sensor. The second temperature sensor is the temperature monitoring device, and the first temperature sensor is electrically connected to the control module. The first temperature sensor is arranged on the inlet side of the in-situ direct-injection nozzle and is located upstream of the in-situ direct-injection nozzle along the fluid flow direction; the first temperature sensor is used to monitor the temperature of the cooling flow rate after heat absorption and to determine whether the superheated vaporization state has been reached.

7. The in-situ injection regeneration cooling system for combustion chambers based on ammonia fuel according to claim 6, characterized in that: Several first temperature sensors are arranged circumferentially at the inlet side of the in-situ direct-fire nozzle; several second temperature sensors are arranged circumferentially at the area of ​​maximum heat load in the cooling channel.

8. The in-situ injection regeneration cooling system for combustion chambers based on ammonia fuel according to claim 1, characterized in that: The cooling channel is provided with several turbulence columns and several ribs, and the turbulence columns are teardrop-shaped turbulence columns. A sleeve structure is provided inside the cooling channel. The sleeve structure is a hollow cylinder. The sleeve structure is horizontally arranged in the cooling channel to connect the flame tube with the external space of the cooling channel, forming an air channel that runs through the cooling channel.

9. The in-situ injection regeneration cooling system for combustion chambers based on ammonia fuel according to claim 1, characterized in that: The cooling channel adopts a counter-flow cooling path layout; the connection end of the cooling channel and the regeneration cooling pipeline is located at the tail of the combustion chamber, and the connection end of the cooling channel and the flame tube is located at the head of the combustion chamber.

10. A control method for an in-situ injection regeneration cooling system for ammonia fuel combustion chamber, characterized in that: The control method for the in-situ injection regeneration cooling system for combustion chambers based on ammonia fuel, as described in any one of claims 1-9, is as follows: The control module will monitor the temperature T at the area of ​​maximum heat load, which is collected in real time by the temperature monitoring device. h and the safe temperature threshold T set within the control module. set Perform a difference comparison; if T h Higher than T set At that time, the PID algorithm module built into the control module calculates the target cooling flow rate Q required to eliminate the temperature difference based on the rate of change and cumulative amount of the temperature deviation. c-t Perform flow rate calculation to obtain the actual cooling flow rate Q in the regeneration cooling pipeline. c The target cooling flow rate Q is calculated and output. c-t Perform comparison calculations to generate action commands to drive the adjustment opening of the second flow regulating device; While performing cooling flow regulation, the control module adjusts the total fuel flow rate Q set within the control module. t Using formula Q f-t =Q t -Q c The calculated target flow rate Q that the nozzle of the flame tube should currently possess f-t The actual cooling flow rate Q in the direct-connected injection pipeline f The target cooling flow rate Q is calculated and output. f-t A comparison calculation is performed to generate an action command to drive the adjustment opening of the first flow regulating device.

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