A thermal management system and method for a hydrogen internal combustion engine fuel injector

Abstract

The present application relates to hydrogen internal combustion engine fuel injection system technical field, especially to a kind of for hydrogen internal combustion engine fuel injector Heat management system and method, contain thermal buffer module, active heat management module, temperature acquisition unit and control module. Thermal buffer module is encapsulated phase change material with annular sealing cavity of coaxial surrounding needle valve guide section, and temperature fluctuation of nozzle is passively smoothed by phase change heat storage and release;Control module is based on engine load change rate to identify heat risk type, drive partition electric heating element directional heat compensation, cooperate phase change buffer to cooperatively control nozzle temperature to preset interval. The present application can solve the problems of existing scheme, such as response delay, control roughness, high energy consumption and inability to cope with complex thermal contradictions.

Description

Technical Field

[0001] This invention relates to the field of hydrogen internal combustion engine fuel injection system technology, and more particularly to a thermal management system and method for hydrogen internal combustion engine fuel injectors. Background Technology

[0002] With the development of zero-carbon power technology, direct-injection hydrogen internal combustion engines have become an important technological route in the internal combustion engine industry. In actual operation, the nozzles of the hydrogen internal combustion engine fuel injectors are directly exposed to the high-temperature environment of the cylinder and need to adapt to a wide range of dynamic changes in operating conditions. Existing technologies face multiple thermal management challenges that are difficult to solve simultaneously: High-load heat accumulation and pre-ignition risk: Under high-load conditions, the nozzle is continuously heated by high-temperature radiation and combustion gas in the cylinder, and the temperature continues to accumulate and rise. Since hydrogen ignition energy is extremely low, when the nozzle surface temperature exceeds the pre-ignition critical point, the newly injected hydrogen will be directly ignited by the high-temperature surface, causing abnormal combustion phenomena such as pre-ignition and pre-combustion, which may cause damage to engine parts in severe cases. Transient thermal shock and seal failure: When the engine suddenly drops from high load to idle speed, the high-temperature nozzle is rapidly cooled by the low-temperature intake air, generating severe thermal shock and alternating thermal stress, which accelerates the fatigue failure of the injector seals; at the same time, hydrogen molecules are small in size and have strong permeability, so even a small failure of the seals can cause hydrogen leakage, which brings serious safety hazards. Low-temperature cold start and icing issues: In cold environments, excessively low nozzle temperatures can affect the accuracy of hydrogen injection, and ice layers can easily form on the nozzle surface; the uneven insulation effect of the ice layer can further induce local overheating of the nozzle, exacerbating thermal management risks. To address the aforementioned issues, existing conventional solutions mostly employ engine coolant circulation cooling or simple external electric heating. Coolant circulation cooling has a slow response time and cannot effectively suppress transient thermal shock; simple external electric heating has low control precision and high energy consumption during continuous operation. Furthermore, both solutions are unidirectional thermal regulation modes, unable to coordinate the complex thermal challenges of multiple scenarios such as heating up, cooling down, and low-temperature start-up, making it difficult to simultaneously meet the multiple requirements of hydrogen internal combustion engine injectors regarding safety and reliability, component lifespan, and low-temperature performance. Summary of the Invention

[0003] The technical problem solved by this invention is to provide a thermal management system and method for hydrogen internal combustion engine fuel injectors, so as to solve the problems of slow response, coarse control, high energy consumption and inability to coordinate complex thermal contradictions in existing solutions.

[0004] The basic solution provided by this invention is a thermal management system for a hydrogen internal combustion engine fuel injector, comprising a thermal buffer module, an active thermal management module, a temperature acquisition unit, and a control module, wherein: The heat buffer module includes an annular sealed cavity inside the fuel injector body; the annular sealed cavity is coaxially surrounding the outer periphery of the needle valve guide section of the fuel injector nozzle; a phase change material is encapsulated inside the annular sealed cavity; the heat buffer module exchanges heat with the nozzle through the melting heat absorption and solidification heat release process of the phase change material. The active thermal management module includes at least one electric heating element, which is attached to a preset heating area of ​​the nozzle and is used to receive heating control signals and perform directional heating on the corresponding area of ​​the nozzle. The temperature acquisition unit is attached to the outer wall of the annular sealed cavity and is used to collect the temperature data of the nozzle in real time and feed it back to the control module. The control module is communicatively connected to the active thermal management module and the temperature acquisition unit, and is also communicatively connected to the engine main control unit of the fuel injector to acquire engine operating condition signals. The control module is used to receive engine operating condition signals and nozzle temperature data, identify the type of thermal risk of the nozzle based at least on the engine load change rate, generate a coordinated control signal according to the identification result, drive the active thermal management module to output the corresponding heating power, and cooperate with the phase change heat storage and release process of the thermal buffer module to coordinate the temperature of the nozzle to be adjusted to a preset temperature range.

[0005] Furthermore, the thermal risk types include rapid cooling risk, heat accumulation risk, and low-temperature cold start risk. The control module identifies the thermal risk type of the nozzle section based on the engine load change rate, and the determination of each thermal risk type includes: Risk assessment of rapid cooling:

[0006] Heat accumulation risk assessment:

[0007] Low-temperature cold start risk assessment:

[0008] If any of the above criteria are not met, it is determined to be a steady-state mode; in, Indicates the rate of change of engine load; This refers to the engine intake air temperature. This represents the current engine load. This refers to the continuous high-load operation time of the engine; The temperature of the nozzle section collected by the temperature acquisition unit; The ambient temperature.

[0009] Furthermore, the control module generates a coordinated control signal based on the identification result, drives the active thermal management module to output the corresponding heating power, and coordinates with the phase change heat storage and release process of the thermal buffer module to regulate the temperature of the nozzle section to within the preset temperature range, including: When a risk of rapid cooling is identified, before the predicted cooling event occurs... At any time, a preheating control signal is output to the active thermal management module, and the heating power duty cycle is set. Heating duration ; When the thermal buffer module is in a buffered state, the phase change material releases latent heat through solidification, which, in conjunction with active heating, reduces the cooling rate of the nozzle section. The nozzle section temperature decrease rate satisfies the following equation:

[0010] in, The duty cycle of the pulse width modulation for the electric heating element. The rate of temperature change at the nozzle section.

[0011] Furthermore, the control module generates a coordinated control signal based on the recognition result, drives the active thermal management module to output the corresponding heating power, and coordinates with the phase change heat storage and release process of the thermal buffer module to regulate the temperature of the nozzle section to within the preset temperature range. This also includes: When a risk of heat accumulation is identified, if the fuel injector itself is equipped with a coolant passage, a cooling adjustment signal is output to increase the coolant flow rate and enhance cooling. If the fuel injector has no coolant passage, it outputs an injection adjustment signal to the engine main control unit to reduce the fuel injection frequency to a preset frequency threshold. Furthermore, the excess heat in the nozzle is absorbed through the melting and heat absorption process of the phase change material within the heat buffer module, thus preventing the nozzle temperature from exceeding the temperature threshold.

[0012] Furthermore, the control module generates a coordinated control signal based on the recognition result, drives the active thermal management module to output the corresponding heating power, and coordinates with the phase change heat storage and release process of the thermal buffer module to regulate the temperature of the nozzle section to within the preset temperature range. This also includes: When a risk of low-temperature cold start is detected, the control module outputs a low-temperature heating control signal to the active thermal management module, wherein the heating power duty cycle is specified. ; Continue heating until the nozzle temperature meets the requirements. When the time comes, stop active heating.

[0013] Furthermore, the control module is also equipped with a closed-loop correction unit, which adjusts the heating power based on the deviation between the measured temperature of the nozzle and the target temperature, as expressed by:

[0014] when At the same time, the duty cycle of the electric heating element is corrected:

[0015] in, The deviation between the measured temperature of the nozzle and the target temperature. Preset target temperature; This is the corrected heating duty cycle. The heating duty cycle before correction. This is the proportional correction factor; the corrected duty cycle. Limited to the range of 0%-100%.

[0016] Furthermore, the phase change material of the heat buffer module is a sodium nitrate-potassium nitrate eutectic salt; the phase change temperature range of the phase change material is... The optimal phase transition temperature is The latent heat of phase transition is not less than The inner wall of the annular sealing cavity is tightly fitted to the outer wall of the needle valve guide section, and the cavity wall is made of a heat-conducting metal material.

[0017] Furthermore, the active thermal management module includes a first electric heating element and a second electric heating element. The first electric heating element is attached to the inner surface of the root of the nozzle portion exposed in the air intake passage, and is used to suppress icing on the outer surface of the nozzle. The second electric heating element is arranged around the outer periphery of the fuel inlet passage of the fuel injector to suppress icing inside the fuel passage; The electric heating element is a flexible thick-film heating element, driven by pulse width modulation mode, and the output heating power is continuously adjusted by adjusting the duty cycle.

[0018] Furthermore, the temperature acquisition unit is a thin-film thermocouple, which is attached to the outer wall of the annular sealed cavity on the side near the nozzle tip. Its sensing surface faces both the nozzle tip and the annular sealed cavity at the same time, so as to simultaneously acquire the nozzle tip temperature and the phase change cavity temperature.

[0019] A thermal management method for a hydrogen internal combustion engine fuel injector, applied to the aforementioned thermal management system for a hydrogen internal combustion engine fuel injector, includes: S1: The temperature data of the nozzle section is collected in real time through the temperature acquisition unit, and the collected nozzle section temperature data is transmitted to the control module; S2: The control module communicates with the external engine main control unit to obtain engine operating condition signals; S3: The control module receives engine operating condition signals and nozzle temperature data, and identifies the type of thermal risk of the nozzle based at least on the engine load change rate. S4: Generate a collaborative control signal based on the identified thermal risk type to drive the active thermal management module to output the corresponding heating power; S5: In conjunction with the phase change material in the heat buffer module, which undergoes melting heat absorption and solidification heat release during the phase change process, the phase change material exchanges heat with the nozzle section, and together regulates the temperature of the nozzle section to within the preset temperature range.

[0020] The technical principle of this invention lies in the following: This invention adopts an integrated thermal management architecture of "passive phase change thermal buffering + active electrothermal zoning regulation + operating condition prediction and collaborative control". Addressing the multi-dimensional thermal risks of hydrogen internal combustion engine fuel injectors under all operating conditions, it smooths temperature fluctuations through passive heat storage and release, actively replenishes heat to cope with extreme low-temperature scenarios, and uses predictive control to achieve proactive risk intervention, collaboratively stabilizing the nozzle temperature within a preset safe range. The specific principle is as follows: Firstly, the passive phase change heat buffering principle: The heat buffering module uses an annular sealed cavity coaxially surrounding the outer periphery of the nozzle needle valve guide section as a carrier, internally encapsulating a phase change material matched to the target temperature range. When the nozzle temperature rises above the phase change temperature due to high-temperature heating inside the cylinder, the phase change material undergoes a solid-liquid phase change, absorbing excess heat from the nozzle through the melting process and storing thermal energy in a near-constant temperature state, thus suppressing the continuous rise in nozzle temperature. When the nozzle temperature drops rapidly below the phase change temperature due to a sudden drop in operating conditions or low-temperature intake cooling, the phase change material undergoes a liquid-solid phase change, releasing the stored latent heat through the solidification process, thus slowing down the cooling rate of the nozzle. Therefore, the passive phase change heat buffering principle utilizes the characteristics of large latent heat and small temperature fluctuations in the phase change process to passively suppress transient temperature fluctuations in the nozzle, weakening the thermal shock amplitude, and achieving adaptive temperature buffering without additional energy consumption.

[0021] Next is the principle of active electric heating zone regulation: The active thermal management module arranges multiple sets of electric heating elements in the high-risk low-temperature area of ​​the nozzle, and uses pulse width modulation mode to achieve continuous adjustment of heating power; heating elements are set for the two types of easily icing areas, namely the exposed surface of the nozzle and the fuel inlet channel, to achieve zoned and directional heating; in scenarios where the passive buffering capacity is insufficient, such as low-temperature cold start and transient rapid cooling, heat is directionally input into the nozzle by outputting a heating signal with a corresponding duty cycle, actively raising or maintaining the nozzle temperature, and making up for the adjustment boundary limitations of passive phase change buffering.

[0022] Finally, the principle of predictive and coordinated control is as follows: The control module synchronously collects real-time temperature data of the nozzle section and engine operating condition signals, using the engine load change rate as the core judgment indicator. Combined with multi-dimensional parameters such as intake air temperature, ambient temperature, and duration of high load, it pre-identifies three types of thermal risk modes: rapid cooling risk, heat accumulation risk, and low-temperature cold start risk. Corresponding control strategies are matched for different risk types: for rapid cooling risk, proactive preheating is triggered in advance, coordinating with the heat release during solidification of the phase change material to suppress the cooling rate; for heat accumulation risk, the phase change material's melting and heat absorption are relied upon, with linkage cooling or injection adjustment as necessary; for low-temperature cold start risk, a continuous heating signal is output until the temperature reaches the target. Simultaneously, a closed-loop correction unit is set up to dynamically fine-tune the heating power based on the deviation between the measured nozzle section temperature and the target temperature, forming a complete control logic of "risk prediction - coordinated execution - closed-loop correction," achieving precise and efficient control of the nozzle section temperature under all operating conditions.

[0023] Beneficial effects: This invention addresses three core technical problems existing in the prior art through architectural innovation and collaborative control, achieving targeted solutions. Specific beneficial effects are as follows: 1. Achieve coordinated management and control of multiple thermal risks under all operating conditions, solving the problem that a single thermal regulation mode cannot take into account thermal conflicts in multiple scenarios. This invention integrates two thermal regulation methods: passive phase change buffering and active electrothermal regulation. It simultaneously addresses three core thermal risks: high-load heat accumulation, transient thermal shock, and low-temperature icing. Under high-load conditions, the melting and heat absorption of the phase change material suppresses nozzle overheating, preventing premature hydrogen combustion caused by excessively high nozzle surface temperatures. During sudden drops in operating conditions, the heat release from the solidification of the phase change material, combined with active preheating, synergistically reduces the nozzle cooling rate, weakens alternating thermal stress, delays seal fatigue failure, and reduces the risk of hydrogen leakage. In low-temperature environments, zoned active heating ensures the nozzle's operating temperature, eliminating the risk of surface and fuel channel icing. This invention overcomes the limitations of traditional single-cooling or single-heating solutions, achieving a unified and synergistic multi-dimensional thermal management system encompassing heating, temperature control, and heat preservation.

[0024] 2. Predictive collaborative control is adopted to improve response speed and control accuracy, solving the problems of slow response, coarse control, and high energy consumption in existing solutions. This invention uses engine load change rate as a predictive basis, triggering control actions in advance before thermal risks occur. Compared with traditional feedback control, it significantly shortens response time and effectively suppresses transient temperature changes. It adopts zoned directional heating and pulse width modulation power regulation, outputting heating power only when a corresponding thermal risk is identified. Combined with the energy-free passive buffer of phase change materials, it significantly reduces the frequency of active regulation and energy consumption. At the same time, the heating power is dynamically fine-tuned based on the measured temperature through a closed-loop correction unit, improving temperature control accuracy and avoiding overheating or underheating. This reduces the overall energy consumption of the system while ensuring thermal management effectiveness.

[0025] 3. An integrated, embedded structural design is adopted to solve the problems of low integration and difficulty in engineering implementation of existing thermal management devices. The thermal buffer module of this invention is directly embedded inside the fuel injector body, and the annular sealed cavity is arranged coaxially around the needle valve guide section, without the need to increase the external volume of the injector. The electric heating element adopts a flexible and fitting installation, which is compatible with the original shape and structure of the injector. The overall system does not require significant changes to the existing injector installation interface and cylinder head layout. It has a compact structure, strong adaptability, and can be directly applied to the upgrade and transformation of existing in-cylinder direct injection hydrogen internal combustion engine injectors. It has low engineering implementation difficulty and is easy to promote and apply in batches. Attached Figure Description

[0026] Figure 1 This is a functional block diagram of an embodiment of the present invention; Figure 2 This is a partial cross-sectional view of the fuel injector according to an embodiment of the present invention. Detailed Implementation

[0027] The following detailed description illustrates the specific implementation method: The reference numerals in the accompanying drawings include: injector body 1, needle valve 2, needle valve guide section 3, annular sealing cavity 4, nozzle section 5, temperature acquisition unit 6, first electric heating element 7, second electric heating element 8.

[0028] The basic implementation examples are as follows: Figure 1 The diagram illustrates a thermal management system for hydrogen internal combustion engine fuel injectors. Applied to high-pressure hydrogen fuel injectors in direct-injection hydrogen internal combustion engines, this system provides full-condition temperature control for the injector nozzle section 5, fundamentally suppressing the risk of hydrogen pre-ignition, mitigating damage to seals from transient thermal shock, and preventing nozzle icing in low-temperature environments. The system comprises four main components: a thermal buffer module, an active thermal management module, a temperature acquisition unit 6, and a control module. The control module is communicatively connected to the external engine main control unit. For ease of description, in this embodiment, the lower end of the fuel injector body 1 is defined as the nozzle section 5, the nozzle section 5 is provided with a reciprocating needle valve 2, and the guide section that cooperates with the inner wall of the nozzle section 5 is the needle valve guide section 3; the upper end of the fuel injector body 1 is provided with a fuel inlet channel for introducing high-pressure hydrogen.

[0029] like Figure 2 As shown, the specific structure, connection relationships, and functions of each module are described below: The thermal buffer module is a passive thermal regulation unit embedded in the fuel injector body 1, and it is the core carrier of the system's temperature buffering capability.

[0030] Structurally, the heat buffer module includes an annular sealed cavity 4 and a phase change material. The annular sealed cavity 4 is located inside the fuel injector body 1 and coaxially surrounds the outer periphery of the needle valve guide section 3 of the fuel injector nozzle section 5. The inner wall of the cavity and the outer wall of the needle valve guide section 3 are integrally formed with a high-temperature resistant and heat-conducting metal material. In this embodiment, a high-temperature resistant stainless steel material is used to ensure thermal conductivity and structural strength. The outer wall of the cavity is sealed and welded to the outer shell of the fuel injector to form a completely sealed and leak-free annular cavity.

[0031] The annular sealed cavity 4 is filled with a phase change material using a vacuum sealing process; in this embodiment, the phase change material is a sodium nitrate-potassium nitrate eutectic salt, and its phase change temperature range is [insert range here]. The optimal phase transition temperature is The latent heat of phase transition is not less than Based on this, a corrosion-resistant coating, such as an alumina ceramic coating, is provided on the inner wall of the annular sealed cavity 4, and the cavity is reserved with a volume expansion compensation space for the solid-liquid conversion of the phase change material to adapt to the volume change during the phase change process.

[0032] In terms of function and role, the heat buffer module achieves directional heat exchange with the nozzle section 5 through the solid-liquid phase change of the phase change material, autonomously slowing down the temperature change rate of the nozzle section 5, and realizing passive temperature buffering without external energy. Specifically: When the nozzle section 5 is heated by the radiation and conduction of the high-temperature combustion gas inside the cylinder, and its temperature rises to the phase change temperature range, the phase change material changes from a solid to a liquid state. Through the melting process, it absorbs the excess heat transferred from the nozzle section 5, storing thermal energy in a near-constant temperature state. This suppresses the continuous rise in the temperature of the nozzle section 5, preventing the nozzle temperature from reaching the pre-ignition critical value too quickly. When the nozzle section 5 is rapidly cooled by the low-temperature intake air, and its temperature drops rapidly below the phase change temperature range, the phase change material changes from a liquid to a solid state. Through the solidification process, it releases the pre-stored latent heat, slowing down the cooling rate of the nozzle section 5, weakening the amplitude of transient thermal shock, and reducing fatigue damage to the seals caused by alternating thermal stress. This module provides basic temperature stability for the nozzle section 5, covering the thermal management needs of most steady-state and small-fluctuation operating conditions.

[0033] The active thermal management module is the active thermal regulation execution unit of the system, used to compensate for the limitations of the regulation boundary of the passive thermal buffer and to cope with the thermal risks in extreme scenarios.

[0034] In terms of structural composition, the active thermal management module includes at least one electric heating element. In this embodiment, a first electric heating element 7 and a second electric heating element 8 are provided, both of which are flexible thick-film heating sheets and are bonded and fixed to the preset heating area of ​​the nozzle part 5 by a high-temperature bonding process; all electric heating elements are driven by pulse width modulation (PWM) mode, and the heating power can be continuously and steplessly adjusted by adjusting the duty cycle of the drive signal.

[0035] The first electric heating element 7 is fitted onto the inner surface of the nozzle portion 5, which is exposed at the root of the air intake passage, and its heating range covers the exposed root area of ​​the nozzle. The second electric heating element 8 is arranged in a ring around the outer periphery of the fuel inlet passage of the fuel injector, and its heating range covers the entire circumferential wall of the fuel intake passage. The power input terminals of both electric heating elements are electrically connected to the power drive output terminal of the control module to receive the heating control signal output by the control module.

[0036] In terms of function and role, the active thermal management module receives coordinated control signals from the control module and performs directional heating on the corresponding area of ​​the nozzle section 5, specifically addressing the problems of low-temperature icing and transient rapid cooling. In low-temperature cold start scenarios, the first electric heating element 7 directionally heats the exposed surface of the nozzle, suppressing frost and ice formation on the outer surface; the second electric heating element 8 heats the entire circumference of the fuel inlet channel, suppressing ice formation inside the fuel channel and ensuring smooth hydrogen flow and injection metering accuracy. In transient rapid cooling scenarios, the module outputs preheating heat at high power to actively replenish the heat loss of the nozzle section 5. Combined with the phase change heat release process of the thermal buffer module, this further reduces the cooling rate of the nozzle section 5 and mitigates the damage to the sealing structure caused by thermal shock.

[0037] The active thermal management module adopts a zoned directional heating architecture, which outputs heat only to high-risk areas. Combined with pulse width modulation for fine power adjustment, it can achieve on-demand heating and effectively reduce system energy consumption.

[0038] Temperature acquisition unit 6 is the temperature sensing unit of the system, providing real-time data support for risk identification and closed-loop control of the control module.

[0039] In terms of structural composition, the temperature acquisition unit 6 employs a patch-type thin-film thermocouple, which is attached to the outer wall of the annular sealed cavity near the nozzle tip. Its sensing surface faces both the nozzle tip and the annular sealed cavity simultaneously, so as to simultaneously acquire the nozzle tip temperature and the phase change cavity temperature. The signal output terminal of the temperature acquisition unit 6 is electrically connected to the analog signal acquisition terminal of the control module, which can convert the acquired temperature data into a corresponding voltage signal and transmit it to the control module.

[0040] In terms of function and role, the temperature acquisition unit 6 collects the temperature data of the nozzle section 5 in real time and feeds it back to the control module, realizing real-time sensing of the nozzle's working status. Since its installation position is adjacent to both the nozzle tip and the phase change material cavity, the temperature data collected by a single sensor can simultaneously characterize the actual working temperature of the nozzle tip and the real-time temperature state of the phase change material. Dual-state temperature sensing can be achieved without the need for additional multiple sensors, which simplifies the internal structural layout of the injector and ensures the real-time nature and representativeness of the temperature data.

[0041] The control module is the core of the entire thermal management system for decision-making and control, and is responsible for condition perception, risk identification, collaborative decision-making and closed-loop correction.

[0042] In terms of structural composition, the control module described in this embodiment is integrated inside the engine control unit (ECU), and achieves bidirectional communication with the ECU via a CAN bus. It is also electrically connected to the active thermal management module and the temperature acquisition unit 6. The control module has built-in preset thermal risk identification logic, collaborative control strategies, and closed-loop correction units, and possesses data processing, logical judgment, and signal output capabilities.

[0043] In terms of function and role, the control module receives engine operating condition signals and nozzle section 5 temperature data, identifies the thermal risk type of nozzle section 5 based at least on the engine load change rate, generates a coordinated control signal based on the identification result, drives the active thermal management module to output corresponding heating power, and coordinates with the phase change heat storage and release process of the thermal buffer module to regulate the temperature of nozzle section 5 to within a preset temperature range. Its specific functional logic is as follows: 1. Data acquisition function: By communicating with the engine main control unit, the engine can acquire operating parameters such as current load, engine load change rate, intake air temperature, ambient temperature, high load continuous operation time, and engine speed in real time; and acquire the measured temperature data of the nozzle section 5 in real time through the temperature acquisition unit 6.

[0044] 2. Thermal Risk Identification Function: Based on preset judgment rules, combined with engine load change rate and multi-dimensional parameters, the thermal state of nozzle section 5 is divided into rapid cooling risk, heat accumulation risk, low temperature cold start risk, and steady-state mode. The judgment logic for each thermal risk type is as follows: Risk assessment of rapid cooling:

[0045] Heat accumulation risk assessment:

[0046] Low-temperature cold start risk assessment:

[0047] If any of the above criteria are not met, it is determined to be a steady-state mode; in, Indicates the rate of change of engine load; This refers to the engine intake air temperature. This represents the current engine load. This refers to the continuous high-load operation time of the engine; The temperature of the nozzle section 5 is collected by the temperature acquisition unit 6; The ambient temperature.

[0048] 3. Coordinated Control Function: For different thermal risk modes, corresponding control strategies are output to achieve coordinated action between active regulation and passive buffering. In the rapid cooling risk model, before the predicted cooling event occurs... At any time, a preheating control signal is output to the active thermal management module, and the heating power duty cycle is set. Heating duration ; The thermal buffer module is in a buffered state. The phase change material releases latent heat through solidification, which, in conjunction with active heating, reduces the cooling rate of nozzle section 5. The temperature drop rate of nozzle section 5 satisfies the following equation:

[0049] in, The duty cycle of the pulse width modulation for the electric heating element. The temperature change rate of nozzle section 5.

[0050] In the heat accumulation risk mode, which corresponds to the scenario where the engine is running under continuous high load and the nozzle is continuously heated by high temperature radiation inside the cylinder, the nozzle temperature is likely to rise and cause hydrogen pre-ignition. At this time, the phase change material in the heat buffer module reaches the phase change range and changes from solid to liquid. It absorbs the excess heat of the nozzle part 5 through the melting process and stores thermal energy in a near constant temperature state, thus suppressing the continuous rise of the nozzle part 5 temperature.

[0051] If the fuel injector is equipped with a coolant passage, it outputs a cooling adjustment signal to increase the coolant flow rate and enhance cooling. If the fuel injector has no coolant passage, an injection adjustment signal is output to the engine main control unit to reduce the fuel injection frequency to a preset frequency threshold, which is 10% in this embodiment. The excess heat of the nozzle section 5 is absorbed by the melting and heat absorption process of the phase change material in the heat buffer module, thus preventing the temperature of the nozzle section 5 from exceeding the temperature threshold; in this embodiment, the temperature threshold is 230°C.

[0052] In the low-temperature cold start risk mode, the control module outputs a low-temperature heating control signal to the active thermal management module, wherein the heating power duty cycle... The first electric heating element 7 and the second electric heating element 8 continuously heat the exposed surface of the nozzle and the fuel passage, respectively. Continue heating until the nozzle section 5 reaches the required temperature. When the time comes, stop active heating.

[0053] In steady-state mode, the active heating output is turned off, and the nozzle temperature is maintained independently by relying solely on the phase change heat storage and release of the thermal buffer module.

[0054] 4. Closed-loop correction function: The control module has a built-in closed-loop correction unit. This unit adjusts the heating power based on the deviation between the measured temperature of the nozzle section 5 and the target temperature. The expression is:

[0055] when At the same time, the duty cycle of the electric heating element is corrected:

[0056] in, The deviation between the measured temperature of nozzle section 5 and the target temperature. The preset target temperature is 190°C in this embodiment; This is the corrected heating duty cycle. Limited to the range of 0%-100%; The heating duty cycle before correction. This is the proportional correction factor, and its value range is... This improves temperature control accuracy and avoids overheating or underheating.

[0057] The control algorithm of this invention can be pre-programmed into the engine controller according to the following logic: Execute once every 10ms: Read dL / dt, , , Load L, Duration of high load

[0058] if dL / dt<-80 and <15: Mode = Risk of rapid cooling Start heating element (PWM= Duration = 1 second else if L>80 and >120 and >210: Pattern = Heat Accumulation Risk If a coolant passage exists → Open the coolant valve wider. Otherwise → Reduce injection frequency by 10% else if <150 and <5: Mode = Low Temperature Start-up Risk Start the heating element (PWM=20%) until... >= 170 else: Mode = Steady State Turn off active heating endif Closed-loop correction: = - 190 (Target temperature 190℃) if | |>10: Fine-tune the heating element PWM by ±5% In other embodiments of this example, the phase change material may also be selected from other matching materials. High-temperature phase change materials within a specific temperature range, such as composite paraffin-based phase change materials and low-melting-point metal-based phase change materials, only need to meet the requirements for phase change temperature range and latent heat index. As an optional implementation, the number of electric heating elements in the active thermal management module can be adjusted according to the injector structure and thermal risk distribution. A single set of heating elements can be set to cover the core low-temperature risk area, or additional heating elements can be added to provide targeted heating for specific areas such as the needle valve seat. As an optional implementation, the control module can also be configured as an external controller independent of the engine main control unit, integrated at the injector wiring harness connector, facilitating upgrades and modifications to existing in-service injectors.

[0059] In another embodiment of this invention, a thermal management method for a hydrogen internal combustion engine fuel injector is further included, applied to the aforementioned thermal management system for a hydrogen internal combustion engine fuel injector, comprising: S1: The temperature data of the nozzle section 5 is collected in real time by the temperature acquisition unit 6, and the collected temperature data of the nozzle section 5 is transmitted to the control module. S2: The control module communicates with the engine main control unit to obtain engine operating condition signals; S3: The control module receives engine operating condition signals and nozzle section 5 temperature data, and identifies the thermal risk type of nozzle section 5 based at least on the engine load change rate. S4: Generate a collaborative control signal based on the identified thermal risk type to drive the active thermal management module to output the corresponding heating power; S5: In conjunction with the phase change heat storage and release process of the phase change material in the heat buffer module, the phase change material and the nozzle 5 exchange heat, and work together to regulate the temperature of the nozzle 5 to the preset temperature range.

[0060] The above are merely embodiments of the present invention. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A thermal management system for a fuel injector in a hydrogen internal combustion engine, characterized in that: It includes a thermal buffer module, an active thermal management module, a temperature acquisition unit, and a control module, wherein: The heat buffer module includes an annular sealed cavity inside the fuel injector body; the annular sealed cavity is coaxially surrounding the outer periphery of the needle valve guide section of the fuel injector nozzle; a phase change material is encapsulated inside the annular sealed cavity; the heat buffer module exchanges heat with the nozzle through the melting heat absorption and solidification heat release process of the phase change material. The active thermal management module includes at least one electric heating element, which is attached to a preset heating area of ​​the nozzle and is used to receive heating control signals and perform directional heating on the corresponding area of ​​the nozzle. The temperature acquisition unit is attached to the outer wall of the annular sealed cavity and is used to collect the temperature data of the nozzle in real time and feed it back to the control module. The control module is communicatively connected to the active thermal management module and the temperature acquisition unit, and is also communicatively connected to the engine main control unit of the fuel injector to acquire engine operating condition signals. The control module is used to receive engine operating condition signals and nozzle temperature data, identify the type of thermal risk of the nozzle based at least on the engine load change rate, generate a coordinated control signal according to the identification result, drive the active thermal management module to output the corresponding heating power, and cooperate with the phase change heat storage and release process of the thermal buffer module to coordinate the temperature of the nozzle to be adjusted to a preset temperature range.

2. A thermal management system for a hydrogen internal combustion engine fuel injector according to claim 1, characterized in that: The thermal risk types include rapid cooling risk, heat accumulation risk, and low-temperature cold start risk. The control module identifies the thermal risk type of the nozzle section based on the engine load change rate. The determination of each thermal risk type includes: Risk assessment of rapid cooling: Heat accumulation risk assessment: Low-temperature cold start risk assessment: If any of the above criteria are not met, it is determined to be a steady-state mode; in, Indicates the rate of change of engine load; This refers to the engine intake air temperature. This represents the current engine load. This refers to the continuous high-load operation time of the engine; The temperature of the nozzle section collected by the temperature acquisition unit; The ambient temperature.

3. A thermal management system for a hydrogen internal combustion engine fuel injector according to claim 2, characterized in that: The control module generates a coordinated control signal based on the identification result, drives the active thermal management module to output the corresponding heating power, and coordinates with the phase change heat storage and release process of the thermal buffer module to regulate the temperature of the nozzle section to within the preset temperature range, including: When a risk of rapid cooling is identified, a preset time is set before the predicted cooling event occurs. At any time, a preheating control signal is output to the active thermal management module, and the heating power duty cycle is set. Heating duration ; When the thermal buffer module is in a buffered state, the phase change material releases latent heat through solidification, which, in conjunction with active heating, reduces the cooling rate of the nozzle section. The nozzle section temperature decrease rate satisfies the following equation: in, The duty cycle of the pulse width modulation for the electric heating element. The rate of temperature change at the nozzle section.

4. A thermal management system for a hydrogen internal combustion engine fuel injector according to claim 2, characterized in that: The control module generates a coordinated control signal based on the identification result, drives the active thermal management module to output the corresponding heating power, and coordinates with the phase change heat storage and release process of the thermal buffer module to regulate the temperature of the nozzle section to within the preset temperature range. This also includes: When a risk of heat accumulation is identified, if the fuel injector itself is equipped with a coolant passage, a cooling adjustment signal is output to increase the coolant flow rate and enhance cooling. If the fuel injector has no coolant passage, it outputs an injection adjustment signal to the engine main control unit to reduce the fuel injection frequency to a preset frequency threshold. Furthermore, the excess heat in the nozzle is absorbed through the melting and heat absorption process of the phase change material within the heat buffer module, thus preventing the nozzle temperature from exceeding the temperature threshold.

5. A thermal management system for a hydrogen internal combustion engine fuel injector according to claim 2, characterized in that: The control module generates a coordinated control signal based on the identification result, drives the active thermal management module to output the corresponding heating power, and coordinates with the phase change heat storage and release process of the thermal buffer module to regulate the temperature of the nozzle section to within the preset temperature range. This also includes: When a risk of low-temperature cold start is detected, the control module outputs a low-temperature heating control signal to the active thermal management module, wherein the heating power duty cycle is specified. ; Continue heating until the nozzle temperature meets the requirements. When the time comes, stop active heating.

6. A thermal management system for a hydrogen internal combustion engine fuel injector according to claim 2, characterized in that: The control module also includes a closed-loop correction unit, which adjusts the heating power based on the deviation between the measured temperature of the nozzle and the target temperature, expressed as: when At the same time, the duty cycle of the electric heating element is corrected: in, The deviation between the measured temperature of the nozzle and the target temperature. Preset target temperature; This is the corrected heating duty cycle. The heating duty cycle before correction. This is the proportional correction factor; the corrected duty cycle. Limited to the range of 0%-100%.

7. A thermal management system for a hydrogen internal combustion engine fuel injector according to claim 1, characterized in that: The phase change material of the heat buffer module is a sodium nitrate-potassium nitrate eutectic salt; the phase change temperature range of the phase change material is... The optimal phase transition temperature is The latent heat of phase transition is not less than The inner wall of the annular sealing cavity is tightly fitted to the outer wall of the needle valve guide section, and the cavity wall is made of a heat-conducting metal material.

8. A thermal management system for a hydrogen internal combustion engine fuel injector according to claim 1, characterized in that: The active thermal management module includes a first electric heating element and a second electric heating element. The first electric heating element is attached to the inner surface of the nozzle exposed at the root of the air intake, and is used to suppress icing on the outer surface of the nozzle. The second electric heating element is arranged around the outer periphery of the fuel inlet passage of the fuel injector to suppress icing inside the fuel passage; The electric heating element is a flexible thick-film heating element, driven by pulse width modulation mode, and the output heating power is continuously adjusted by adjusting the duty cycle.

9. A thermal management system for a hydrogen internal combustion engine fuel injector according to claim 1, characterized in that: The temperature acquisition unit is a thin-film thermocouple, which is attached to the outer wall of the annular sealed cavity on the side near the nozzle tip. Its sensing surface faces both the nozzle tip and the annular sealed cavity at the same time, so as to simultaneously acquire the nozzle tip temperature and the phase change cavity temperature.

10. A thermal management method for a hydrogen internal combustion engine fuel injector, applied to a thermal management system for a hydrogen internal combustion engine fuel injector as described in any one of claims 1-9, characterized in that: include: S1: The temperature data of the nozzle section is collected in real time through the temperature acquisition unit, and the collected nozzle section temperature data is transmitted to the control module; S2: The control module communicates with the engine main control unit to obtain engine operating condition signals; S3: The control module receives engine operating condition signals and nozzle temperature data, and identifies the type of thermal risk of the nozzle based at least on the engine load change rate. S4: Generate a collaborative control signal based on the identified thermal risk type to drive the active thermal management module to output the corresponding heating power; S5: In conjunction with the phase change material in the heat buffer module, which undergoes melting heat absorption and solidification heat release during the phase change process, the phase change material exchanges heat with the nozzle section, and together regulates the temperature of the nozzle section to within the preset temperature range.

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