Strong pre-cooling system and control method for turbo-based combined cycle engine

Abstract

The present disclosure relates to the field of aerospace propulsion technology, and particularly provides a strong precooling system and control method for a turbine-based combined cycle engine. The system comprises: a main precooling flow path comprising a main heat sink for heat exchange between a liquid hydrogen heat sink and a precooling medium, and a main precooling medium pump; a secondary precooling flow path connected in parallel with the main precooling flow path, comprising a secondary heat sink for heat exchange between a hydrogen fuel heat sink and the precooling medium, and a secondary precooling medium pump; a cooperative heat exchanger for controllable heat exchange between the liquid hydrogen heat sink and a hydrocarbon fuel heat sink to adjust the temperature of the liquid hydrogen heat sink entering the main heat sink; a health management unit configured to determine a fault risk monitoring result based on multi-modal monitoring data of the main precooling flow path; and a control unit configured to perform risk control on the main precooling flow path, the secondary precooling flow path and / or the cooperative heat exchanger in response to the fault risk monitoring result. The present disclosure can significantly improve the safety, reliability and mission execution efficiency of the strong precooling system.

Description

Technical Field

[0001] This disclosure relates to the field of aerospace propulsion technology, and in particular to a powerful precooling system and control method for a turbine-based combined cycle engine. Background Technology

[0002] As a key power unit for wide-speed-range aircraft, the turbine-based combined cycle (TBCC) engine relies on efficient transitions between turbine and ramjet modes for stable operation across a wide air envelope. A powerful pre-cooling system, by deeply cooling the high-temperature incoming air before the compressor, significantly improves the operating upper limit of the turbine engine and is a crucial technical means to ensure smooth mode transitions.

[0003] A typical intensive precooling system consists of a precooler, a radiator, and a precooling medium pump. Its working principle is as follows: the precooling medium absorbs heat from the mainstream air in the precooler, and then transfers this heat to the fuel heat sink, which is typically liquid hydrogen, in the radiator. However, to address the risks of precooling medium solidification, structural fatigue and leakage due to the extremely low temperature (approximately 20K) of liquid hydrogen, as well as insufficient pump power and vicious cycles, intensive precooling systems generally employ a "dual backup" or "hardware redundancy" design. This typically involves two parallel flow paths, a primary and a secondary one, each containing a primary / secondary pump and a primary / secondary radiator, respectively. During flight, if the control system detects a failure in the primary precooling flow path, it immediately executes a switching logic: shutting down the primary precooling flow path and simultaneously activating the secondary precooling flow path. Based on this, intensive precooling systems often suffer from design redundancy, resource waste, and rudimentary fault response strategies. Summary of the Invention

[0004] This disclosure is made in view of the above-mentioned problems. This disclosure provides a strong precooling system and control method for a turbine-based combined cycle engine.

[0005] According to one aspect of this disclosure, a strong precooling system for a turbine-based combined cycle engine is provided, the strong precooling system being located in the airflow direction of the turbine-based combined cycle engine, the strong precooling system comprising:

[0006] The main precooling flow path includes a main radiator that allows heat exchange between the liquid hydrogen heat sink and the precooling medium, and a main precooling medium pump driven by the power extraction shaft of the turbine-based combined cycle engine.

[0007] The secondary precooling flow path, connected in parallel with the main precooling flow path, includes a secondary radiator for exchanging heat between the hydrogen fuel heat sink and the precooling medium, and a secondary precooling medium pump driven by an electric motor.

[0008] A co-exchange heat exchanger is installed before the precooling medium enters the main radiator to enable controllable heat exchange between the liquid hydrogen heat sink and the hydrocarbon fuel heat sink, thereby regulating the temperature of the liquid hydrogen heat sink entering the main radiator.

[0009] A health management unit is configured to determine the failure risk monitoring results of the main precooling flow path based on the multimodal monitoring data of the main precooling flow path;

[0010] The control unit, which is communicatively connected to the health management unit, is configured to perform risk control on the main precooling flow path, the secondary precooling flow path, and / or the collaborative heat exchanger in response to the fault risk monitoring results. The risk control includes proactive adjustment before a fault occurs and hierarchical collaborative control after a fault occurs.

[0011] According to another aspect of this disclosure, a control method for a strong precooling system applied to the aforementioned turbine-based combined cycle engine is provided, comprising:

[0012] The health management unit determines the fault risk monitoring results of the main precooling flow path based on the multimodal monitoring data of the main precooling flow path;

[0013] In response to the fault risk monitoring results, the control unit performs risk control on the main precooling flow path, the secondary precooling flow path, and / or the co-processing heat exchanger. The risk control includes proactive adjustment before a fault occurs and graded co-processing control after a fault occurs.

[0014] As will be described in detail below, the powerful precooling system of the turbine-based combined cycle engine according to an embodiment of the present disclosure includes a main precooling flow path comprising a main radiator for heat exchange between the liquid hydrogen heat sink and the precooling medium, and a main precooling medium pump driven by the power extraction shaft of the turbine-based combined cycle engine. A secondary precooling flow path connected in parallel with the main precooling flow path includes a secondary radiator for heat exchange between the hydrocarbon fuel heat sink and the precooling medium, and a secondary precooling medium pump driven by an electric motor. A co-exchange heat exchanger disposed before the precooling medium enters the main radiator is used to enable controllable heat exchange between the liquid hydrogen heat sink and the hydrocarbon fuel heat sink, thereby regulating the temperature of the liquid hydrogen heat sink entering the main radiator. Based on this, heat exchange between the main liquid hydrogen heat sink and the hydrocarbon fuel heat sink on the precooling medium can be achieved through the main and secondary precooling flow paths, and dual heat sink heat exchange between the liquid hydrogen heat sink and the hydrocarbon fuel heat sink can be achieved through the co-exchange heat exchanger, thereby actively regulating the temperature of the liquid hydrogen heat sink entering the radiator and maximizing the utilization of both fuel heat sinks. Meanwhile, the health management unit can determine the fault risk monitoring results of the main precooling flow path based on the multimodal monitoring data of the main precooling flow path; the control unit, which is connected to the health management unit in communication, can respond to the fault risk monitoring results and perform risk control on the main precooling flow path, the secondary precooling flow path and / or the cooperating heat exchanger. The risk control includes active adjustment before the fault occurs and hierarchical cooperating control after the fault occurs. Based on this, fault monitoring, active adjustment and hierarchical cooperating control are introduced, which significantly improves the safety, reliability and mission execution efficiency of the strong precooling system, realizes the leap from "passive redundancy" to "active-passive cooperating protection", and improves the safety and mission adaptability of the turbine-based combined cycle engine under complex operating conditions.

[0015] It should be understood that both the foregoing general description and the following detailed description are exemplary and intended to provide further illustration of the claimed technology. Attached Figure Description

[0016] The above and other objects, features, and advantages of this disclosure will become more apparent from the more detailed description of the embodiments thereof in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the disclosure and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0017] Figure 1 A schematic diagram of the architecture of a strong precooling system for a turbine-based combined cycle engine provided in an exemplary embodiment of this disclosure is shown.

[0018] Figure 2 A schematic diagram of the structure of the synergistic heat exchanger in low heat transfer mode provided in an exemplary embodiment of the present disclosure is shown;

[0019] Figure 3A schematic diagram of the high heat transfer mode of the synergistic heat exchanger provided in an exemplary embodiment of this disclosure is shown.

[0020] Figure 4 A flowchart illustrating the control method provided by an exemplary embodiment of this disclosure is shown.

[0021] Figure label:

[0022] 100-Main precooling flow path, 110-Main precooling medium pump, 120-Main radiator, 121-Electric heating element, 200-Secondary precooling flow path, 210-Secondary precooling medium pump, 211-Battery, 220-Secondary radiator, 300-Co-processing heat exchanger, 310-Hydrocarbon fuel insulated oil tank, 320-Heat exchange tube, 330-Modible partition structure, 340-Agitator, 400-Health management unit, 500-Control unit, 601-Turbine-based combined cycle engine, 602-Power extraction shaft, 603-Precooler. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this disclosure more apparent, exemplary embodiments according to this disclosure will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this disclosure, and not all embodiments of this disclosure. It should be understood that this disclosure is not limited to the exemplary embodiments described herein.

[0024] It should be understood that the steps described in the method embodiments of this disclosure may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this disclosure is not limited in this respect.

[0025] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below. It should be noted that the concepts of "first", "second", etc., used in this disclosure are only used to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0026] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0027] The names of messages or information exchanged between multiple devices in the embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of such messages or information.

[0028] Liquid hydrogen (LH2) is considered the most efficient and ideal fuel heat sink due to its extremely high specific heat capacity and extremely low initial temperature. However, using liquid hydrogen as a heat sink also brings serious technical challenges, mainly the following problems:

[0029] 1. Risk of Precooling Medium Solidification: Liquid hydrogen has an extremely low temperature (approximately 20K). When the heat load of the precooling system (such as flight Mach number or altitude) changes drastically, the precooling medium (usually liquid working fluids such as water or ethylene glycol) may solidify due to localized excessively low temperatures during heat exchange with liquid hydrogen in the radiator, leading to blockage. This will drastically degrade radiator efficiency, causing the precooler outlet temperature, i.e., the turbine engine inlet airflow temperature, to exceed the limit, potentially causing irreversible structural damage to the engine.

[0030] 2. Structural Fatigue and Leakage Risks: The extremely low temperature environment of liquid hydrogen subjectes radiator materials to enormous thermal stress cycles, easily inducing low-temperature fatigue failure in localized areas, leading to precooling medium leakage. Leakage of the precooling medium not only causes the precooling system to fail but may also come into contact with high-temperature components, posing a systemic safety risk.

[0031] 3. Insufficient Pump Power and a Vicious Cycle: The precooling medium pump is typically driven by the power take-off (PTO) shaft of a turbine engine to obtain greater power. However, under complex flight envelopes and varying operating conditions, the engine may be unable to provide sufficient extracted power in certain situations. This will trigger a dangerous vicious cycle: "decreased precooling medium flow rate → decreased precooling capacity → increased engine inlet temperature and decreased thrust → further decrease in extractable power," ultimately potentially leading to uncommanded engine shutdown.

[0032] To address the aforementioned risks, conventional forced precooling systems generally employ a "dual backup" or "hardware redundancy" design. This approach sets up two parallel flow paths, a primary and a secondary one, each containing a primary / secondary pump and a primary / secondary radiator. During flight, if the control system detects a failure in the primary precooling flow path, it immediately executes switching logic: shutting down the primary precooling flow path and simultaneously activating the secondary precooling flow path. However, this forced precooling system has a significant drawback:

[0033] 1. Design Redundancy and Waste of Resources: The secondary precooling flow path and its components are typically designed with "minimum safe operating" capability, only used to ensure engine parameter reduction operation and safe return. This "hardware backup" mode is completely idle during the normal operation of the main precooling flow path, failing to fully realize its potential value and resulting in significant weight and space redundancy.

[0034] 2. Crude Fault Response Strategy: Conventional fault response logic is too "one-size-fits-all." Regardless of the type and severity of the fault (e.g., a minor local blockage or a serious media leak), the same "switch and return" strategy is used. This simplistic approach lacks flexibility and precision, failing to address different fault scenarios in a tiered manner, which may lead to unnecessary task interruptions and performance degradation.

[0035] Therefore, in order to solve the above problems, the present disclosure provides a strong precooling system for a turbine-based combined cycle engine. By introducing fault prediction, active adjustment and graded response mechanisms, the safety, reliability and mission execution efficiency of the strong precooling system are significantly improved. It realizes the leap from "passive redundancy" to "active-passive coordinated protection", and improves the safety and mission adaptability of the turbine-based combined cycle engine under complex operating conditions.

[0036] This disclosure provides an exemplary embodiment of a powerful precooling system for a turbine-based combined cycle engine. Figure 1 A schematic diagram of the architecture of a strong precooling system for a turbine-based combined cycle engine provided in an exemplary embodiment of this disclosure is shown. Figure 1 As shown, the strong precooling system is located in the direction of the airflow of the turbine-based combined cycle engine 601, and the strong precooling system includes:

[0037] The main precooling flow path 100 includes a main radiator 120 that allows the liquid hydrogen heat sink to exchange heat with the precooling medium and a main precooling medium pump 110 driven by the power extraction shaft 602 of the turbine-based combined cycle engine 601.

[0038] The secondary precooling flow path 200, connected in parallel with the main precooling flow path 100, includes a secondary radiator 220 for exchanging heat between the hydrocarbon fuel heat sink and the precooling medium and a secondary precooling medium pump 210 driven by an electric motor.

[0039] The co-exchange heat exchanger 300 is installed before the precooling medium enters the main radiator 120 to enable controllable heat exchange between the liquid hydrogen heat sink and the hydrocarbon fuel heat sink, so as to regulate the temperature of the liquid hydrogen heat sink entering the main radiator 120.

[0040] The health management unit 400 is configured to determine the failure risk monitoring results of the main precooling flow path 100 based on the multimodal monitoring data of the main precooling flow path 100;

[0041] The control unit 500, which is communicatively connected to the health management unit 400, is configured to perform risk control on the main precooling flow path 100, the secondary precooling flow path 200, and / or the co-processing heat exchanger 300 in response to the results of fault risk monitoring. The risk control includes proactive adjustment before a fault occurs and hierarchical co-processing control after a fault occurs.

[0042] Specifically, such as Figure 1 As shown, the forced precooling system provided in this embodiment mainly includes a main precooling flow path 100, a secondary precooling flow path 200, a co-processing heat exchanger 300, a health management unit 400, and a control unit 500. The hardware architecture of this forced precooling system adopts a dual-flow-path backup structure and a dual-heat sink coupling design.

[0043] The dual-flow backup structure specifically includes a main precooling flow path 100 and a secondary precooling flow path 200 arranged in parallel. The main precooling flow path 100 includes a main radiator 120 for heat exchange between the liquid hydrogen heat sink and the precooling medium, and a main precooling medium pump 110 driven by the engine power extraction shaft 602. The secondary precooling flow path 200 includes a secondary radiator 220 for heat exchange between the hydrocarbon fuel heat sink and the precooling medium, and a secondary precooling medium pump 210 driven by an electric motor. Here, the precooling medium can be selected according to actual needs, and this embodiment does not specifically limit it. In the method of this embodiment, the precooling medium can typically be a liquid working fluid such as water or ethylene glycol.

[0044] The main precooling medium pump 110 can be driven by the power extraction shaft 602 (PTO) of the turbine-based combined cycle engine 601, providing high-power, high-flow-rate medium circulation capability. The main radiator 120 is a high-efficiency heat exchanger where the precooling medium transfers the heat absorbed to the liquid hydrogen (LH2) heat sink. Several electric heating elements 121 can be integrated inside the main radiator 120 for precise local heating when needed.

[0045] The main precooling flow path 100 is also connected to the precooler 603 before the engine compressor for circulating the precooling medium, forming a complete precooling cycle.

[0046] The secondary precooling flow path 200 serves as a backup and complement to the main precooling flow path, operating in parallel with it. In the secondary precooling flow path 200, the secondary precooling medium pump 210 is driven by an electric motor and equipped with a battery 211. This secondary precooling medium pump 210 operates independently of the power extraction shaft 602 of the turbine-based combined cycle engine 601, and can provide power when the main precooling medium pump 110 is underpowered or fails. The precooling medium transfers heat to a hydrocarbon fuel (such as aviation kerosene) heat sink in the secondary radiator 220. Here, since the freezing point of hydrocarbon fuel is much higher than the temperature of liquid hydrogen, using hydrocarbon fuel as the secondary heat sink fundamentally avoids the problem of medium solidification in the secondary precooling flow path 200.

[0047] The dual heat sink coupling design specifically involves a co-current heat exchanger 300, through which the liquid hydrogen heat sink must pass before entering the main radiator 120. In this co-current heat exchanger 300, the liquid hydrogen heat sink and the hydrocarbon fuel heat sink undergo controlled heat exchange. This dual heat sink coupling design aims to actively regulate the inlet temperature of the liquid hydrogen heat sink in the main radiator 120 and maximize the utilization of both fuel heat sinks.

[0048] This dual heat sink coupling design breaks through the traditional "hardware redundancy" approach, enabling the secondary precooling flow path 200 to participate in regulation and coordinated work while the main precooling flow path 100 is operating normally. This achieves full utilization of hardware resources, maximizes the utilization rate of the total fuel heat sink, and thus optimizes the precooling efficiency and resource utilization rate of the strong precooling system.

[0049] The Health Management System (HMS) 400 acts as the brain of the strong precooling system, which is used to acquire multimodal monitoring data of the main precooling flow path 100 in real time, and determine the failure risk monitoring results of the main precooling flow path 100 based on the multimodal monitoring data of the main precooling flow path 100.

[0050] Here, the health management unit 400 can collect the above-mentioned multimodal monitoring data through sensors (such as temperature sensors, pressure sensors, flow meters, vibration sensors, etc.) deployed at various points in the main precooling flow path. The above-mentioned multimodal monitoring data includes, but is not limited to, temperature sensor data, pressure sensor data, flow sensor data, and vibration sensor data.

[0051] The above-mentioned fault risk monitoring results may include, but are not limited to, the status of the main precooling flow path and the prediction results of potential faults (such as solidification of the precooling medium and leakage).

[0052] The control unit 500 is communicatively connected to the health management unit 400, receives fault risk monitoring results from the health management unit 400, and, in response to the fault risk monitoring results, performs risk control on the main precooling flow path 100, the secondary precooling flow path 200, and / or the co-current heat exchanger 300. This risk control may take into account real-time operating data from the turbine-based combined cycle engine.

[0053] Here, the aforementioned fault risk monitoring results may include risk monitoring results prior to the occurrence of a fault (also known as risk prediction results), and risk control includes proactive adjustments prior to the occurrence of a fault. For example, in response to the risk monitoring results prior to the occurrence of a fault, the control unit 500 may perform risk control on the main precooling flow path 100, the secondary precooling flow path 200, and / or the co-exchange heat exchanger 300. By proactively taking preventative measures, the control unit adjusts the main precooling flow path 100, the secondary precooling flow path 200, and / or the co-exchange heat exchanger 300 to eliminate the possibility of a fault, thereby achieving the effect of risk prevention.

[0054] The aforementioned fault risk monitoring results can include risk monitoring results after a fault occurs, and risk control includes hierarchical collaborative control after a fault occurs. For example, the control unit 500 can respond to the risk monitoring results after a fault occurs by performing risk control on the main precooling flow path 100, the secondary precooling flow path 200, and / or the collaborative heat exchanger 300, and promptly implement hierarchical collaborative control according to the fault level corresponding to the risk monitoring results after a fault occurs, in order to deal with different levels of faults and solve the problem of overly "one-size-fits-all" fault response logic in related technologies.

[0055] Based on this, in this embodiment, the control unit 500 can avoid various typical faults in advance through the "prevention-oriented" active protection layer, fundamentally reducing the probability of failure of the strong precooling system; the hierarchical collaborative control ensures that the response to different faults is accurate and effective, avoiding task interruption caused by minor faults, thereby improving the safety and reliability of the strong precooling system.

[0056] Meanwhile, facing complex and ever-changing flight environments and operating conditions, the risk control provided by the embodiments of this disclosure includes proactive adjustment before a failure occurs and graded collaborative control after a failure occurs. This effectively solves the problems of precooling medium solidification and main radiator fatigue damage that may be caused by liquid hydrogen heat sinks, while avoiding performance loss and safety risks caused by simple switching of conventional dual backup systems, significantly improving the reliability and adaptability of the strong precooling system. The intelligent and refined control characteristics of this risk control enable the strong precooling system and the turbine-based combined cycle engine to operate more smoothly and efficiently, improving the overall performance of the aircraft and the mission success rate, and enhancing the adaptability of the strong precooling system to flight missions.

[0057] According to the technical solution provided in the embodiments of this disclosure, in the strong precooling system of the turbine-based combined cycle engine, the main precooling flow path includes a main radiator for heat exchange between the liquid hydrogen heat sink and the precooling medium, and a main precooling medium pump driven by the power extraction shaft of the turbine-based combined cycle engine. The secondary precooling flow path connected in parallel with the main precooling flow path includes a secondary radiator for heat exchange between the hydrocarbon fuel heat sink and the precooling medium, and a secondary precooling medium pump driven by an electric motor. A co-exchange heat exchanger set before the precooling medium enters the main radiator is used to enable controllable heat exchange between the liquid hydrogen heat sink and the hydrocarbon fuel heat sink to regulate the temperature of the liquid hydrogen heat sink entering the main radiator. Based on this, heat exchange between the main liquid hydrogen heat sink and the hydrocarbon fuel heat sink on the precooling medium can be achieved through the main precooling flow path and the secondary precooling flow path, and dual heat sink heat exchange between the liquid hydrogen heat sink and the hydrocarbon fuel heat sink can be achieved through the co-exchange heat exchanger to actively regulate the temperature of the liquid hydrogen heat sink entering the radiator and maximize the utilization of the two fuel heat sinks. Meanwhile, the health management unit can determine the fault risk monitoring results of the main precooling flow path based on the multimodal monitoring data of the main precooling flow path; the control unit, which is connected to the health management unit in communication, can respond to the fault risk monitoring results and perform risk control on the main precooling flow path, the secondary precooling flow path and / or the cooperating heat exchanger. The risk control includes active adjustment before the fault occurs and hierarchical cooperating control after the fault occurs. Based on this, fault monitoring, active adjustment and hierarchical cooperating control are introduced, which significantly improves the safety, reliability and mission execution efficiency of the strong precooling system, realizes the leap from "passive redundancy" to "active-passive cooperating protection", and improves the safety and mission adaptability of the turbine-based combined cycle engine under complex operating conditions.

[0058] In some embodiments, the failure risk monitoring results include the predicted risk probability that the precooling medium will solidify within the main radiator 120;

[0059] The health management unit 400 is also configured to use a pre-built failure risk assessment model based on multimodal monitoring data to determine the predicted risk probability of the precooling medium solidifying within the main radiator 120.

[0060] The control unit 500 is also configured to proactively adjust the main precooling flow path 100, the secondary precooling flow path 200, and / or the co-current heat exchanger 300 in response to a predicted risk probability of condensation of the precooling medium within the main radiator 120 before a failure occurs.

[0061] Specifically, the aforementioned fault risk assessment model may include a lightweight algorithm that integrates physical models and data-driven models (such as machine learning algorithms) to monitor the status of the strong precooling system in real time and predict the probability of potential faults (such as precooling medium solidification or leakage). Based on this, the fault risk monitoring results include the predicted probability of precooling medium solidification within the main radiator 120.

[0062] Here, the physical model may include, but is not limited to, the precooling medium solidification critical temperature model, the thermal stress fatigue model, etc., based on heat transfer and fluid mechanics, and the embodiments disclosed herein do not specifically limit this.

[0063] Data-driven models can include, but are not limited to, neural networks such as Long Short-Term Memory (LSTM) networks. By learning from historical flight data and fault data, they can predict future trends in system states, such as "the probability of solidification in a certain area of ​​the main radiator 120 within the next 5 seconds is 85%".

[0064] The control unit 500 employs compression techniques such as knowledge distillation and model pruning to ensure that lightweight algorithms can run efficiently on onboard chips with limited computing power, and reserves an over-the-air (OTA) upgrade interface to facilitate continuous optimization of subsequent algorithms.

[0065] The forced precooling system operates continuously in active protection mode. The health management unit 400 can analyze the multimodal monitoring data of the sensors in real time and use the built-in fault risk assessment model to assess the risk of the multimodal monitoring data, determining the predicted risk probability of the precooling medium solidifying in the main radiator 120. At this time, before the fault actually occurs, the control unit 500 can take proactive preventive measures in response to the predicted risk probability of the precooling medium solidifying in the main radiator 120, and actively adjust the main precooling flow path 100, the secondary precooling flow path 200, and / or the co-exchange heat exchanger 300 before the fault occurs.

[0066] In some embodiments, Figure 2 A schematic diagram of the structure of the synergistic heat exchanger in low heat transfer mode provided in an exemplary embodiment of this disclosure is shown, as follows: Figure 2 As shown, the co-current heat exchanger 300 includes:

[0067] Hydrogen fuel insulated tank 310;

[0068] Heat exchange tube 320 is located at the bottom of the hydrocarbon fuel insulated oil tank 310 and is used for the flow of liquid hydrogen heat sink.

[0069] The movable partition structure 330 is installed inside the hydrocarbon fuel insulated oil tank 310 and above the heat exchange tube 320, and is used to control the contact area between the heat exchange tube 320 and the hydrocarbon fuel heat sink.

[0070] A stirrer 340 is disposed inside the hydrocarbon fuel insulated tank 310 and above the movable partition structure 330 to promote the flow of hydrocarbon fuel heat sink.

[0071] Specifically, such as Figure 2As shown, one specific embodiment of the co-exchange heat exchanger 300 cleverly utilizes the structure of the hydrocarbon fuel tank. The heat exchange tube 320 through which the liquid hydrogen heat sink flows is positioned at the bottom of the hydrocarbon fuel insulated tank 310. A movable baffle structure 330 can separate the heat exchange tube 320 from most of the hydrocarbon fuel heat sink within the hydrocarbon fuel insulated tank 310. A stirrer 340 is also installed inside the hydrocarbon fuel insulated tank 310; the rotation of the stirrer 340 promotes the flow of the hydrocarbon fuel heat sink.

[0072] The aforementioned movable baffle structure 330 can be a set of louvered baffles, or other structures that can change the contact area between the heat exchange tube 320 and the hydrocarbon fuel heat sink. The heat exchange between the liquid hydrogen heat sink and the hydrocarbon fuel heat sink can be controlled by adjusting the opening degree of the movable baffle structure and / or the rotation speed of the stirrer.

[0073] The heat exchange mode of the co-heat exchanger 300 may include a low heat exchange mode and a high heat exchange mode. The control unit is also configured to shut down the movable partition structure and the agitator if the heat exchange mode of the co-heat exchanger 300 is a low heat exchange mode, and to turn on the movable partition structure and the agitator if the heat exchange mode of the co-heat exchanger 300 is a high heat exchange mode.

[0074] like Figure 2 As shown, the heat exchange mode of the co-current heat exchanger 300 is a low heat exchange mode. When the main precooling flow path 100 is operating normally, the movable baffle structure 330 is closed and stops rotating. At this time, the heat exchange tube 320 only exchanges heat with the stationary, small-volume hydrocarbon fuel heat sink within the movable baffle structure 330 through natural convection. Due to the extremely small heat exchange, the temperature rise of the liquid hydrogen heat sink is not significant, thus ensuring that the liquid hydrogen heat sink still has a very strong heat absorption capacity when it enters the main radiator 120.

[0075] Figure 3 A schematic diagram of the high heat transfer mode of the synergistic heat exchanger provided in an exemplary embodiment of this disclosure is shown, as follows: Figure 3 As shown, when the health management unit 400 predicts a risk of solidification in the main radiator 120, the control unit 500 instructs the movable partition structure 330 to open and simultaneously activates the stirrer 340. At this time, the heat exchange tube 320 undergoes forced convection heat exchange with the large-volume hydrocarbon fuel heat sink, which is forcibly stirred throughout the hydrocarbon fuel insulated tank 310. The heat exchange volume increases dramatically, causing the temperature of the liquid hydrogen heat sink to rise significantly before entering the main radiator 120, thereby reducing or eliminating the risk of solidification of the pre-cooled medium at its source.

[0076] Based on this, the embodiments of this disclosure can achieve continuous adjustment of the heat transfer power of the co-exchange heat exchanger 300 by controlling the opening degree of the movable partition structure and the rotation speed of the stirrer.

[0077] For example, proactive adjustments prior to a failure include at least one of the following:

[0078] Increase the speed of the main precooling medium pump 110 or open the auxiliary precooling flow path 200 to increase the circulation flow rate of the precooling medium;

[0079] The electric heating element installed in the main heat sink 120 is activated to pulse heat the low-temperature area in the main heat sink 120 corresponding to the predicted risk probability.

[0080] Specifically, the control unit 500 can also be configured to slightly increase the speed of the main precooling medium pump 110 or slightly open the secondary precooling flow path 200 to increase the total circulation flow rate of the precooling medium, increase the flow rate of the precooling medium in the low temperature zone, and suppress the formation of solidification nuclei.

[0081] The main radiator 120 contains an electric heating element 121, and the control unit 500 can also be configured to activate the electric heating element 121 in the main radiator 120 to perform precise, low-power pulse heating on the area most prone to solidification (corresponding to the predicted risk probability).

[0082] For example, the heat exchange mode of the co-heat exchanger 300 may include a low heat exchange mode and a high heat exchange mode, and the control unit is also configured to switch the heat exchange mode of the co-heat exchanger 300 by adjusting the opening of the movable baffle structure and / or the rotation speed of the stirrer.

[0083] Active adjustments prior to a failure may also include controlling the co-exchange heat exchanger 300 to enter a high heat exchange mode to increase the temperature at which the precooling medium enters the main radiator 120.

[0084] Based on this, the powerful precooling system provided in this embodiment can achieve the first level of protection: fault prediction and proactive adjustment. The health management unit predicts the risk of localized solidification or leakage of the precooling medium based on historical and real-time data. Before a fault actually occurs, the control unit proactively takes preventative measures, such as adjusting the precooling medium flow rate, adjusting the heat exchange power of the co-exchange heat exchanger to increase the liquid hydrogen temperature, or activating the localized electric heating element in the main radiator, thereby preventing the fault from escalating.

[0085] If the active protection (level 1 protection) fails to completely prevent the fault, or if a sudden fault occurs, the control unit will enter hierarchical collaborative control.

[0086] For example, the control unit 500 is also configured to increase the flow rate of hydrocarbon fuel through the secondary radiator 220 and / or activate an electric heating element disposed in the main radiator 120 in response to a fault risk monitoring result of a minor fault, in order to compensate for the performance loss of the main precooling flow path 100.

[0087] Specifically, a minor fault can lead to a localized decrease in the efficiency of the main radiator. The health management unit 400 detects a slight blockage in a channel of the main radiator 120, resulting in a 5% decrease in heat exchange efficiency. At this point, the control unit 500 determines the fault risk monitoring result as a minor fault and will not switch the main pre-cooling flow path. Instead, it instructs an increase in the flow rate of the hydrocarbon fuel heat sink passing through the auxiliary radiator 220, allowing the auxiliary pre-cooling flow path to share some of the heat dissipation workload to compensate for the performance loss of the main pre-cooling flow path and maintain a constant engine inlet total temperature. Simultaneously, the electric heating element installed in the main radiator 120 is activated to initiate pulse heating on the blocked area in an attempt to clear the blockage.

[0088] For example, the control unit 500 is also configured to start the auxiliary precooling medium pump 210 and work in conjunction with the main precooling medium pump 110 in response to a fault risk monitoring result of a moderate fault.

[0089] Specifically, a moderate fault could be caused by insufficient power from the main precooling medium pump. The health management unit 400 detects that the main precooling medium pump 110's speed is decreasing due to insufficient engine power extraction, resulting in insufficient total flow to meet demand. The control unit 500 determines the fault risk monitoring result as a moderate fault. At this time, the control unit 500 starts the motor-driven auxiliary precooling medium pump 210 and adjusts its speed to work in coordination with the main precooling medium pump 110. Both pumps jointly provide the required total flow, with the main precooling medium pump 110 providing the base flow and the auxiliary precooling medium pump 210 supplementing the difference, achieving "dynamic coordination" of pump functions rather than "rigid switching."

[0090] For example, the control unit 500 is also configured to shut down the main precooling flow path 100 and fully enable the secondary precooling flow path 200 in response to a fault risk monitoring result indicating a severe fault.

[0091] Specifically, a severe malfunction could involve a medium leak in the main radiator. The health management unit 400 detects a rupture in the main radiator 120, with precooling medium leaking towards liquid hydrogen, based on monitoring data from pressure and chemical sensors. The control unit 500 determines the malfunction risk monitoring result to be severe and triggers the highest safety response. The control unit 500 immediately closes all valves in the main precooling flow path 100 and the main precooling medium pump 110, while simultaneously activating the auxiliary precooling flow path 200 (auxiliary precooling medium pump 210 and auxiliary radiator 220) at full power. The auxiliary precooling flow path uses hydrocarbon fuel as a heat sink and is inherently safe. Simultaneously, the control unit 500 signals the engine control system, requesting the engine to reduce to a safe operating speed, and alerts the pilot, indicating the need for a return to base for maintenance.

[0092] Based on this, the strong precooling system provided in this disclosure can achieve a second level of protection: fault classification and collaborative response. When a fault occurs, the control unit executes graded collaborative control according to the type and severity of the fault. For example, for a minor fault (such as a localized decrease in the performance of the main radiator): the main precooling flow path is not switched, but compensation is made by increasing the heat dissipation load of the auxiliary radiator (such as increasing the flow rate of hydrocarbon fuel through the auxiliary radiator), or by activating the pulse electric heating element in the main radiator to eliminate local blockages and maintain the overall system performance. For a moderate fault (such as insufficient power of the main precooling medium pump): the main pump is not shut down, but the auxiliary precooling medium pump is activated, allowing it to work in conjunction with the precooling medium pump to meet the total flow requirements of the system and achieve dynamic sharing of power and flow. For a severe fault (such as a medium leak in the main radiator): the highest safety strategy is executed, the main precooling flow path is immediately shut down, the auxiliary precooling flow path is fully opened, and the engine deceleration protection procedure is triggered to ensure aircraft safety. Based on this, this disclosure can divide the response mechanism into three levels according to the severity of the fault, avoiding the problems of excessive performance loss and insufficient control of safety risks caused by simple switching in conventional dual-backup systems.

[0093] In some embodiments, the strong precooling system further includes an energy recovery circuit configured to store excess electrical energy generated by the power extraction shaft 602 of the turbine-based combined cycle engine 601 into a battery associated with the auxiliary precooling medium pump 210 during the cruise operation of the turbine-based combined cycle engine 601.

[0094] Specifically, to ensure the absolute reliability of the secondary precooling flow path 200 as the last line of defense, this embodiment also incorporates an energy coupling mechanism. During the cruise phase of a flight mission, the engine power is sufficient, and the power extraction shaft 602 of the turbine-based combined cycle engine 601 has excess power generation capacity. At this time, the strong precooling system charges this excess electrical energy into the battery 211 of the secondary precooling medium pump 210 through a rectifier charging circuit. This not only extends the range of the secondary precooling flow path 200 and enhances its reliability as a backup, but also achieves comprehensive energy management and utilization, improving the energy efficiency of the entire propulsion system.

[0095] Based on this, the strong precooling system provided in this disclosure can achieve a third level of protection: energy coupling and passive backup. Energy coupling involves storing excess electrical energy generated by the power extraction shaft in the battery of the auxiliary precooling medium pump via a rectifier circuit during the cruise phase when engine power is sufficient, extending the independent operating time of the auxiliary flow path and enhancing its reliability as a backup. Simultaneously, through a coordinated heat exchanger and dual-pump drive energy coupling design, a smooth transition and optimal system performance recovery are achieved during failures. Passive backup retains the complete auxiliary precooling flow path as a final safety guarantee, but within the framework of this disclosure, its activation timing and method are more precise and efficient.

[0096] As can be seen from the foregoing, the strong precooling system provided in this disclosure constructs an "active-passive collaborative" precooling safety architecture, breaks through the traditional redundancy design concept, proposes a three-level protection logic of "fault monitoring-active adjustment-passive backup", highlights the design concept of "prevention first and rapid response", predicts potential faults through the machine learning model of the active protection layer, and combines the optimized backup strategy of the passive protection layer to achieve graded response and precise handling of faults, providing a new technical solution for the reliable operation of the strong precooling system of TBCC engine.

[0097] The beneficial effects of this strong precooling system are:

[0098] (1) Turning passive into active: Through fault monitoring and active adjustment, the traditional “fault-switching-return” mode is transformed into “prediction-adjustment-fault avoidance”, which greatly improves the continuity and reliability of the mission.

[0099] (2) Maximize resource utilization: The secondary precooling flow path and dual heat sink coupling design are not only backups, but also participate in system regulation during normal operation (such as preheating liquid hydrogen), realizing the functional utilization of hardware redundancy and avoiding dead weight.

[0100] (3) Precision of response strategy: The hierarchical collaborative response mechanism takes the most reasonable measures for faults of different severity, avoiding the overly conservative strategy of returning to base regardless of the size of the fault, and improving the mission flexibility and economy of the aircraft.

[0101] (4) Improved system efficiency: The dual heat sink coupling design and energy recovery mechanism optimize the efficiency of the entire thermal management system and energy system, making the system operation more robust and efficient.

[0102] This exemplary embodiment also provides a control method for a strong precooling system applied to the aforementioned turbine-based combined cycle engine. Figure 4 A flowchart illustrating the control method provided in an exemplary embodiment of this disclosure is shown. Figure 4 As shown, the control method includes:

[0103] S401, the health management unit determines the failure risk monitoring results of the main precooling flow path based on the multimodal monitoring data of the main precooling flow path;

[0104] S402, the control unit responds to the fault risk monitoring results and performs risk control on the main precooling flow path, the secondary precooling flow path and / or the co-processing heat exchanger. The risk control includes active adjustment before the fault occurs and hierarchical co-processing control after the fault occurs.

[0105] Specifically, the health management unit can determine the fault risk monitoring results of the main precooling flow path based on the multimodal monitoring data of the main precooling flow path; the control unit, which is connected in communication with the health management unit, can respond to the fault risk monitoring results and perform risk control on the main precooling flow path, the secondary precooling flow path, and / or the cooperating heat exchanger. The risk control includes active adjustment before the fault occurs and hierarchical cooperating control after the fault occurs. Based on this, fault monitoring, active adjustment, and hierarchical cooperating control are introduced, which significantly improves the safety, reliability, and mission execution efficiency of the strong precooling system, realizes the leap from "passive redundancy" to "active-passive cooperating protection", and improves the safety and mission adaptability of the turbine-based combined cycle engine under complex operating conditions.

[0106] The above description is merely an illustration of some embodiments of this disclosure and the technical principles employed. Those skilled in the art should understand that the scope of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features disclosed in this disclosure that have similar functions.

[0107] While specific embodiments of this disclosure have been described in detail by way of example, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A powerful precooling system for a turbine-based combined cycle engine, characterized in that, The strong precooling system is located in the direction of the airflow of the turbine-based combined cycle engine, and the strong precooling system includes: The main precooling flow path includes a main radiator that allows heat exchange between the liquid hydrogen heat sink and the precooling medium, and a main precooling medium pump driven by the power extraction shaft of the turbine-based combined cycle engine. The secondary precooling flow path, connected in parallel with the main precooling flow path, includes a secondary radiator for exchanging heat between the hydrocarbon fuel heat sink and the precooling medium, and a secondary precooling medium pump driven by an electric motor. A co-exchange heat exchanger is installed before the precooling medium enters the main radiator to enable controllable heat exchange between the liquid hydrogen heat sink and the hydrocarbon fuel heat sink, thereby regulating the temperature of the liquid hydrogen heat sink entering the main radiator. A health management unit is configured to determine the failure risk monitoring results of the main precooling flow path based on the multimodal monitoring data of the main precooling flow path; The control unit, communicatively connected to the health management unit, is configured to perform risk control on the main precooling flow path, the secondary precooling flow path, and / or the collaborative heat exchanger in response to the fault risk monitoring results. The risk control includes proactive adjustment before a fault occurs and tiered collaborative control after a fault occurs. The synergistic heat exchanger includes: Hydrogen fuel insulated tank; The heat exchange tube is located at the bottom of the hydrocarbon fuel insulated tank and is used to circulate the liquid hydrogen heat sink. A movable partition structure is installed inside the hydrocarbon fuel insulated oil tank and located above the heat exchange tube, used to control the contact area between the heat exchange tube and the hydrocarbon fuel heat sink; A stirrer is installed inside the hydrocarbon fuel insulated tank and above the movable partition structure to promote the flow of the hydrocarbon fuel heat sink. The heat exchange mode of the synergistic heat exchanger includes a low heat exchange mode and a high heat exchange mode. The control unit is also configured to switch the heat exchange mode of the synergistic heat exchanger by adjusting the opening of the movable baffle structure and / or the rotation speed of the stirrer. The proactive adjustments made before the fault occurs include controlling the collaborative heat exchanger to enter a high heat exchange mode to increase the temperature of the precooling medium entering the main radiator.

2. The forced precooling system as described in claim 1, characterized in that, The failure risk monitoring results include the predicted probability of the precooling medium solidifying in the main radiator. The health management unit is also configured to determine the predicted risk probability of the precooling medium solidifying in the main radiator based on the multimodal monitoring data using a pre-built failure risk assessment model. The control unit is also configured to proactively adjust the main precooling flow path, the secondary precooling flow path, and / or the co-current heat exchanger in response to a predicted risk probability that the precooling medium will solidify within the main radiator before the failure occurs.

3. The forced precooling system as described in claim 2, characterized in that, The proactive adjustments made before the fault occurs include at least one of the following: Increase the speed of the main precooling medium pump or open the secondary precooling flow path to increase the circulation flow rate of the precooling medium; The electric heating element installed in the main heat sink is activated to pulse heat the low-temperature region in the main heat sink corresponding to the predicted risk probability.

4. The forced precooling system as described in claim 1, characterized in that, The control unit is also configured to, in response to a fault risk monitoring result indicating a minor fault, increase the flow rate of hydrocarbon fuel through the secondary radiator and / or activate an electric heating element disposed within the main radiator to compensate for performance loss in the main precooling flow path.

5. The forced precooling system as described in claim 1, characterized in that, The control unit is also configured to start the auxiliary precooling medium pump and work in coordination with the main precooling medium pump in response to the fault risk monitoring result being a moderate fault.

6. The forced precooling system as described in claim 1, characterized in that, The control unit is also configured to shut down the main precooling flow path and fully enable the secondary precooling flow path in response to a fault risk monitoring result indicating a severe fault.

7. The forced precooling system as described in any one of claims 1 to 6, characterized in that, The strong precooling system also includes an energy recovery circuit, configured to store excess electrical energy generated by the power extraction shaft of the turbine-based combined cycle engine into a battery that is paired with the auxiliary precooling medium pump during the cruise operation of the turbine-based combined cycle engine.

8. A control method for a strong precooling system applied to a turbine-based combined cycle engine according to any one of claims 1 to 6, characterized in that, include: The health management unit determines the fault risk monitoring results of the main precooling flow path based on the multimodal monitoring data of the main precooling flow path; In response to the fault risk monitoring results, the control unit performs risk control on the main precooling flow path, the secondary precooling flow path, and / or the co-processing heat exchanger. The risk control includes proactive adjustment before a fault occurs and graded co-processing control after a fault occurs.

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