Air inlet system for supercharged hydrogen-ammonia hybrid fuel engine

Abstract

The invention discloses an air inlet system for a supercharged hydrogen-ammonia mixed fuel engine. The air inlet system aims at solving the problems of hydrogen-ammonia fuel contradictory characteristics and supercharged engine cold start. The core structure of the high-thermal-conductivity aluminum alloy manifold comprises an integrated die-casting high-thermal-conductivity aluminum alloy manifold body, and a main gas inlet cavity, an ammonia gas supply rail, a pre-buried PTC electric heating wire, a hydrogen injection connector, a mixed reinforcing structure and a closed-loop control system composed of multiple sensors and an ECU are integrated in the body. The ECU regulates and controls the cooling intensity, the heating source and the electric auxiliary heating power according to the working conditions, and hydrogen preignition prevention, ammonia gas full gasification, cold start quick response and full-working-condition uniform mixing are achieved. The system is high in integration level and low in energy consumption, and enables the supercharged hydrogen ammonia engine to stably operate under all working conditions.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of new internal combustion engines, and specifically relates to an air intake system for a supercharged hydrogen-ammonia mixed fuel engine. The system deeply integrates the combustion characteristics, physical characteristics and engine thermal management requirements of hydrogen and ammonia, and solves multiple challenges such as hydrogen pre-ignition, backfire, poor ammonia gasification, uneven mixing and NOx control through a highly integrated active thermal management structure and integrated cold start electric auxiliary heating device. BACKGROUND

[0002] The ignition energy of hydrogen is only 0.02 mJ under the equivalent ratio condition. This characteristic makes it an ideal auxiliary fuel for mixed combustion with fuels such as ammonia, methanol and natural gas. The ultra-low ignition energy causes hydrogen to be easily ignited by the hot spots in the intake port, leading to abnormal combustion such as pre-ignition and backfire. Hydrogen-ammonia mixed fuel is an important technical path for internal combustion engines to achieve zero-carbon fuel applications. However, there are significant differences and even contradictions between hydrogen and ammonia in terms of physical and chemical properties, which bring unprecedented complexity to engine design: 1. Hydrogen characteristics Extremely low minimum ignition energy 0.02 mJ: makes it extremely sensitive to any hot surface in the cylinder or intake port, and extremely prone to pre-ignition and backfire.

[0003] Extremely high flame propagation speed about 3 m / s: once ignited, the combustion is extremely rapid, and if abnormal combustion occurs, the pressure peak is high and the destructive power is strong.

[0004] Wide flammable range 4%-75%: the risk window for forming flammable mixture in the intake port is larger.

[0005] 2. Ammonia characteristics Extremely high latent heat of vaporization 1370 kJ / kg: liquid ammonia vaporization absorbs heat, which can cause a sharp drop in intake port temperature, leading to poor gasification, uneven mixing, incomplete combustion and wear.

[0006] Extremely low flame propagation speed about 0.07 m / s: slow combustion is the main obstacle to stable combustion and combustion process organization, and requires hydrogen ignition and boost.

[0007] Higher octane value RON>130: excellent anti-knock performance, allowing the engine to use high compression ratio and supercharging technology to improve efficiency.

[0008] Nitrogen element exists: under certain high-temperature oxygen-rich conditions, combustion may produce nitrogen oxides NOx.

[0009] 3. Internal combustion engine technical design attributes Supercharging technology: To improve power density, supercharging is an inevitable choice. However, the intake temperature after supercharging increases significantly, which may be > 150°C, greatly increasing the risk of hydrogen early combustion.

[0010] Thermal management system: Modern engines have precise temperature zone cooling circuits, with low temperature circuits at about 60-80°C and high temperature circuits at about 90-105°C, providing a foundation for integrated thermal design.

[0011] Mixture preparation: Uniform and controllable mixture is the premise of efficient and clean combustion. There is a contradiction between the rapid diffusion of hydrogen and the delayed gasification of ammonia.

[0012] Although using high-temperature engine coolant to heat the ammonia rail is an efficient and energy-saving solution, in the cold start condition, the engine has not yet reached the normal operating temperature, and the coolant in the high-temperature cooling circuit is close to the ambient temperature, which cannot provide the required heat for ammonia gasification. At this time, liquid ammonia cannot be effectively gasified in the ice-cold ammonia rail and injector, resulting in difficult engine start, shaking, or even failure to start. The existing technology uses external preheating or independent heater, which has the problems of slow response, low integration, high energy consumption and additional components. Therefore, an auxiliary cold start heat source with fast response and precise control is embedded in the integrated scheme to assist the hydrogen-ammonia engine to realize full-condition practicality.

[0013] The existing technology uses a separate scheme to solve the above problems, such as external intercooler, independent heating ammonia rail, complex injection strategy, etc., which has the disadvantages of system redundancy, response lag, high energy consumption, high cost and limited effect. There is currently a lack of an integrated solution that collaboratively manages and utilizes the characteristics of hydrogen and ammonia from the root. SUMMARY

[0014] The core purpose of the present application is to solve the technical bottleneck of the existing supercharged hydrogen-ammonia engine intake system, and to provide a highly integrated and intelligent collaborative intake manifold assembly: for hydrogen early combustion: create a safe temperature environment of <85°C for the main intake cavity through active cooling, physically eliminate the hot ignition source; for ammonia gasification: through waste heat heating and cold start electric auxiliary heating dual heat source, ensure that ammonia gas is completely gasified without liquid droplets before injection; for uneven mixing: through a special mixing enhancement structure, realize molecular-level uniform mixing of hydrogen and ammonia gas; For full-condition adaptation: through an intelligent control system, coordinate each component to adapt to different conditions of cold start, small load and large load, and finally realize stable, efficient and clean operation of the hydrogen-ammonia engine.

[0015] To achieve the above purpose, the present application adopts the following technical solutions: An air intake system for a supercharged hydrogen-ammonia mixed fuel engine, comprising a manifold body, which is internally integrated with: a main air intake cavity for flowing supercharged air and hydrogen-ammonia mixed gas; a first flow channel system, the flow channels of which tightly wrap the main air intake cavity in a three-dimensional honeycomb network structure, the first cooling liquid inlet and the first cooling liquid outlet of the first flow channel system being connected to an engine low-temperature cooling circuit of 60-80 DEG C respectively for flowing low-temperature cooling medium to actively cool the main air intake cavity; an ammonia gas supply rail for conveying liquid ammonia, the inner wall of which is subjected to ammonia corrosion-resistant treatment; a second flow channel system, the flow channels of which tightly wrap the ammonia gas supply rail in a double-layer spiral coil structure, the second cooling liquid inlet and the second cooling liquid outlet of the second flow channel system being connected to an engine high-temperature cooling circuit of 90-105 DEG C respectively for flowing high-temperature cooling medium to actively heat the ammonia gas supply rail; an electric auxiliary heating element, which is embedded in the wall of the ammonia gas supply rail or in a high-thermal-conductivity insulation layer between the wall of the ammonia gas supply rail and the second flow channel system, for assisting in heating the ammonia gas supply rail during cold start; wherein the first flow channel system and the second flow channel system are isolated by the solid material of the manifold body and are not in communication with each other.

[0016] In the present application, the first flow channel system maximizes the heat exchange area through the honeycomb network cooling flow channels. The low-temperature cooling liquid flowing therein guarantees the core function of cooling the intake air and preventing pre-ignition; the second flow channel system adopts a double-layer spiral heating flow channel, which tightly winds around the ammonia gas rail. The engine high-temperature cooling liquid flowing therein utilizes waste heat to provide the main heat source for ammonia gasification.

[0017] Further, the electric auxiliary heating element is a PTC electric heating wire, and further preferably, the power of the PTC electric heating wire is 300-800 W, and the PTC electric heating wire is uniformly arranged along the length direction of the ammonia gas supply rail, and the spacing between adjacent two sections of the PTC electric heating wire is 80-120 mm.

[0018] Further, the temperature sensor assembly and an engine control unit ECU are further included; the temperature sensor assembly comprises: a temperature sensor T1 arranged inside the ammonia gas supply rail for monitoring the temperature of the medium in the ammonia gas supply rail; a temperature sensor T2 arranged at the outlet of the main air intake cavity for monitoring the temperature of the hydrogen-ammonia mixed gas; a temperature sensor T3 arranged in the engine cylinder head cooling circuit for monitoring the temperature of the high-temperature cooling medium; A temperature sensor T4 is arranged at the second cooling liquid inlet of the second flow channel system to monitor the temperature of the high-temperature cooling medium entering the second flow channel system; the temperature sensors T1, T2, T3 and T4 are signal-connected to the ECU, and the ECU is further electrically connected with a cooling circuit actuator and a relay; the cooling circuit actuator comprises a low-temperature circuit electronic water pump, a low-temperature circuit electronic thermostat and a high-temperature circuit electronic valve, and the relay is connected in series with the electric auxiliary heating element to form a closed-loop active thermal management system.

[0019] In the present application, the ECU engine control unit is the control center of the system. All sensor signals are received, calculated by an internal model, and actively controlled cooling water pump, thermostat, heating valve and PTC electric heating wire relay to realize intelligent thermal management in all working conditions.

[0020] Further, the engine control unit ECU is programmed to: Cold start control logic: when receiving an engine start signal and the temperature sensor T3 detection value < the first set threshold value 45-55℃, control the relay to turn on, start the electric auxiliary heating element, and adjust the power of the electric auxiliary heating element through PWM pulse width modulation to maintain the temperature sensor T1 detection value at 75-85℃; Hot switching control logic: when the temperature sensor T3 detection value > the second set threshold value 65-75℃, gradually reduce the power of the electric auxiliary heating element until the relay is turned off, and switch to heating the ammonia gas supply rail only through the second flow channel system; Safety cooling control logic: when the temperature sensor T2 detection value > the safety threshold value 80-85℃, the cooling intensity of the main air inlet cavity is enhanced, the safety cooling threshold value is 80-85℃, and 65℃ is the advance intervention threshold value.

[0021] Further, the manifold body is further integrated with a hydrogen injection interface, an ammonia injector mounting seat and a mixing enhancement structure; the hydrogen injection interface is located downstream of the ammonia gas supply rail and is wrapped by the flow channel of the first flow channel system in the corresponding area; the mixing enhancement structure is arranged between the hydrogen injection interface and the main air inlet cavity outlet, which is a Venturi tube type mixing throat or a guide cyclone vane; the ammonia injector mounting seat is located upstream of the hydrogen injection interface.

[0022] Further, the manifold body is made of high-thermal-conductivity aluminum alloy by integrated die casting, and preferably the thermal conductivity coefficient of the manifold body is ≥150 W / (m·K).

[0023] Further, the inner wall surface of the main air inlet cavity is a turbulent flow enhancement type surface, and further preferably the turbulent flow enhancement type surface is a micro-vortex tooth structure with a depth of 0.3-0.8mm and a pitch of 1.5-2.5mm or a roughened surface with a roughness Ra1.6-6.3μm.

[0024] Furthermore, the ammonia supply rail is treated with an anodic oxide coating or a polytetrafluoroethylene coating. The coating thickness is 8-15 μm, and the coating's ammonia corrosion resistance is such that it shows no corrosion marks after immersion in 99.9% pure ammonia at 25°C for 1000 hours.

[0025] Furthermore, the constriction angle of the Venturi-type mixed larynx is 25-35°, the larynx diameter is 10-15mm, and the expansion angle is 10-15°.

[0026] The present invention also provides a turbocharged hydrogen-ammonia hybrid fuel engine, including a turbocharger, an intake system, a cylinder head and a cylinder. The intake system is the intelligent thermal management hydrogen-ammonia engine intake manifold assembly with cold start electric auxiliary heating function. The outlet of the turbocharger is connected to the inlet of the main intake chamber, and the outlet of the main intake chamber is connected to the inlet of the cylinder.

[0027] The present invention has the following beneficial effects: This invention uses active cooling to keep the main intake chamber temperature below 85°C, completely eliminating the risk of hydrogen pre-ignition and backfire; and uses dual heat source heating to stabilize the ammonia rail temperature at 75-90°C, allowing ammonia to achieve a near 100% vaporization rate. Full operating condition coverage: It can meet the ammonia vaporization requirements during cold start, and the engine will not vibrate or stall throughout its entire life cycle from cold to hot. High integration and lightweight: A single component integrates six functions: intake manifold, intercooler auxiliary, ammonia rail, ammonia heating, hydrogen injection interface, and mixer; Optimal energy utilization: Under normal operating conditions, the ammonia rail is heated by engine waste heat with no additional energy consumption; the cold start electric auxiliary heating uses PTC elements with controllable power and no risk of overheating; Excellent combustion and emission performance: The hydrogen-ammonia mixing uniformity is >90%, the combustion efficiency is improved by 8%-12%, and the engine power density is improved by 10%-15%; at the same time, NOx emissions are reduced by 30%-40%, meeting the China VI and above emission standards.

[0028] To more clearly illustrate the structural features and effects of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of one embodiment of the present invention.

[0030] Reference: 1 - manifold body, 2 - main intake cavity, 3 - first flow channel system, 4 - first coolant inlet, 5 - first coolant outlet, 6 - ammonia supply rail, 7 - second flow channel system, 8 - second coolant inlet, 9 - second coolant outlet, 10 - electric auxiliary heating element, 11 - ammonia injector mounting seat, 12 - hydrogen injection interface, 13 - mixing enhancement structure, 14 - temperature sensor T1, 15 - temperature sensor T2, 16 - temperature sensor T3, 17 - temperature sensor T4, 18 - ECU, 19 - relay, 20 - cylinder. DETAILED DESCRIPTION

[0031] The application will be further described in conjunction with the drawings and relevant knowledge, and a clear and complete description will be made. Obviously, the described application is only a part of the embodiments of the application, not all embodiments.

[0032] The application belongs to the technical field of novel internal combustion engines, and solves multiple challenges such as hydrogen early combustion, tempering, poor ammonia gasification, uneven mixing, and NOx control through a highly integrated active heat management structure and an integrated cold start electric auxiliary heating device.

[0033] The application aims to provide a highly integrated and intelligent collaborative intake manifold assembly (an intake system for a supercharged hydrogen-ammonia mixed fuel engine). Based on the deep characteristics of hydrogen and ammonia fuel, the engine's own heat management resources are used to create the most suitable microenvironment for hydrogen and ammonia through precise active heat control in one component; and an electric auxiliary heating system is particularly integrated to overcome the cold start problem. A continuous cooling environment is provided for hydrogen to prevent hot surface ignition, and a continuous heating environment is provided for ammonia to ensure complete gasification, and an instant heat source is provided by the electric heating wire during cold start, which also plays a role in intercooling auxiliary temperature rise / drop, and finally realizes stable, efficient and clean operation of the hydrogen-ammonia engine under all operating conditions.

[0034] The application is an intelligent heat management hydrogen-ammonia engine intake manifold assembly with a cold start electric auxiliary heating function based on the characteristics of hydrogen-ammonia fuel, which comprises a manifold body made of high thermal conductivity aluminum alloy by integrated casting. The body is integrated with the following core structures: Main intake cavity and active cooling system: the main intake cavity 2 serves as the main passage for air and mixed gas, and its wall surface is designed as a turbulent flow enhancement surface such as a micro-vortex tooth or roughening treatment to enhance heat exchange and mixing.

[0035] The cryogenic cooling channel tightly wraps the main intake chamber 2 with a three-dimensional honeycomb mesh structure. This structure has the largest specific surface area, enabling extremely high heat exchange efficiency. It connects to the engine's cryogenic cooling circuit, utilizing the cryogenic coolant at 65°C to continuously and powerfully remove heat from the pressurized air and air-fuel mixture, ensuring that the main intake chamber wall temperature remains below 85°C, always within the safe temperature boundary of hydrogen, completely eliminating hot spots and ignition sources. Simultaneously, this design assists or replaces the traditional external intercooler.

[0036] Ammonia supply, active vaporization, and cold start auxiliary system: The ammonia supply rail 6 is fully integrated and embedded inside the manifold body, and its flow channel undergoes special anti-ammonia corrosion treatment, such as an anodized coating. The high-temperature heating flow channel tightly wraps the ammonia rail with a double-layer spiral coil structure. This structure provides uniform heating without dead zones. Pre-embedded electric auxiliary heating element 10: High-resistance heating wires are pre-embedded in the wall of the ammonia supply rail, or in a layer of high thermal conductivity insulating material, such as ceramic-filled thermally conductive adhesive, between the ammonia rail wall and the high-temperature heating flow channel. These heating wires are evenly arranged along the length of the ammonia rail to ensure uniform heating. Under normal operating conditions: connected to the engine's high-temperature cooling circuit, the waste heat from the engine cylinder head outlet water (~95°C) is used to heat the ammonia rail from all directions. This ensures that the liquid ammonia absorbs sufficient heat during its flow and is completely converted into a saturated or superheated gaseous state before being ejected, fundamentally preventing the generation of liquid ammonia droplets. Cold start / low temperature operation: When the engine coolant temperature is detected to be below a set threshold, such as 50°C, the ECU automatically activates the PTC heating wire to directly and rapidly heat the ammonia rail with resistance, raising the ammonia rail temperature to the required vaporization temperature within tens of seconds, ensuring a smooth engine start. After the engine is running and the high-temperature coolant temperature rises, the electric auxiliary heating system automatically shuts off and switches to waste heat heating mode.

[0037] Hydrogen-ammonia mixing synergistic structure: The ammonia injector mounting base 11 is integrated and also surrounded by a high-temperature heating channel to prevent the nozzle from freezing. The hydrogen injection port 12 is located a certain distance downstream of the ammonia injector, and this area is kept at a low temperature by a cooling channel. More preferably, the hydrogen injection port is located 20-30 mm downstream of the ammonia injection port.

[0038] Hybridization Enhancement Design: A Venturi-type mixing throat or flow-guiding swirl vane is designed between the hydrogen and ammonia injection points. Utilizing the negative pressure and turbulence generated by the accelerated airflow, the freshly ejected gaseous ammonia and hydrogen are drawn in and pulverized, achieving rapid and uniform mixing at the nanoscale.

[0039] Intelligent thermal management control system: Temperature sensors are installed at the low-temperature coolant inlet, high-temperature coolant inlet, main intake chamber outlet, and inside the ammonia rail. Sensor signals are fed into the engine control unit (ECU). The ECU calculates the heat load in real time using an algorithm model and actively adjusts: the speed of the electronic water pump in the low-temperature circuit and the opening of the electronic thermostat to control the cooling intensity of the main intake manifold; and the opening of the electronic valve in the high-temperature circuit to control the heating intensity of the ammonia rail. The on / off state and power of the PTC heating wire relay are modulated using PWM (Pulse Width Modulation) to provide precise and rapid auxiliary heating during cold starts.

[0040] This invention enables intelligent thermal management under all operating conditions. For example, during cold starts, it uses PTC heating to increase ammonia rail heating; under low loads, it reduces the main air duct cooling intensity to increase the intake air temperature and promote ammonia combustion; and under high loads, it provides full cooling to prevent pre-ignition.

[0041] Specifically as follows: Reference Figure 1 As shown, an intake system for a turbocharged hydrogen-ammonia hybrid fuel engine (an intelligent thermal management hydrogen-ammonia engine intake manifold assembly with cold-start electric auxiliary heating function) includes a manifold body 1, wherein the manifold body 1 integrates the following internally: Main intake chamber 2 is used for the flow of pressurized air and hydrogen-ammonia mixture; The first flow channel system 3 has its flow channel tightly enclosing the main intake chamber 2. The first coolant inlet 4 and the first coolant outlet 5 of the first flow channel system 3 are respectively connected to the engine low-temperature cooling circuit for circulating low-temperature cooling medium to actively cool the main intake chamber 2. Ammonia supply rail 6 is used to transport liquid ammonia; The second flow channel system 7 has its flow channel tightly wrapped around the ammonia supply rail 6. The second coolant inlet 8 and the second coolant outlet 9 of the second flow channel system 7 are respectively connected to the engine high-temperature cooling circuit for circulating high-temperature cooling medium to actively heat the ammonia supply rail 6. An electric auxiliary heating element 10 is embedded in the wall of the ammonia supply rail 6 or located between the wall of the ammonia supply rail 6 and the second flow channel system 7, and is used to assist in heating the ammonia supply rail 6 during cold start; wherein, the first flow channel system 3 and the second flow channel system 7 are isolated by the solid material of the manifold body 1.

[0042] In this invention, the manifold body is preferably made of high thermal conductivity aluminum alloy with a thermal conductivity of ≥150W / (m・K) and is integrally die-cast to avoid leakage risks and increased thermal resistance caused by splicing multiple parts; as mentioned above, the main air intake chamber, the first flow channel system cooling, the ammonia supply rail, the second flow channel system heating, the electric auxiliary heating element and the hybrid reinforcement structure are integrated internally.

[0043] Further optimization involves designing the inner wall of the intake chamber structure with micro-vortex teeth depth of 0.3-0.8mm or a roughened surface—creating turbulence when the airflow passes through, enhancing the heat exchange efficiency with the cooling channel. In another optimization, the first channel system 3 employs a three-dimensional honeycomb mesh structure with a pore size of 5-8mm and a wall thickness of 1-1.5mm, tightly wrapping the main intake chamber to maximize the heat exchange area (specific surface area > 500m² / m³). The channel connects to the engine's low-temperature cooling circuit (60-80℃), continuously removing heat from the pressurized air through the low-temperature coolant. The high-temperature air (150-200℃) output from the turbocharger enters the main intake chamber and efficiently exchanges heat with the low-temperature coolant (around 65℃) within the honeycomb channel, reducing the intake temperature to 75-80℃, consistently below the hydrogen pre-ignition threshold of 85℃. This also avoids excessive cooling leading to a decrease in combustion efficiency. This system can replace the traditional external intercooler, reducing the risk of pipeline leaks and providing a faster cooling response.

[0044] The second flow channel system 7 adopts a double-layer spiral coil structure with a pitch of 15-20mm and a diameter of 6-8mm, tightly wound around the ammonia supply rail 6 to ensure heating without dead zones; the flow channel connects to the engine's high-temperature cooling circuit 90-105℃ and the cylinder head outlet, using the engine's waste heat to provide basic heat for ammonia vaporization.

[0045] In a preferred embodiment of the present invention, the electric auxiliary heating element 10 is a PTC heating wire, which is uniformly arranged along the length of the ammonia supply rail 6. The electric auxiliary heating element is either embedded in the wall of the ammonia supply rail or filled with thermally conductive adhesive using a high thermal conductivity insulating layer ceramic.

[0046] In a preferred embodiment of the present invention, a temperature sensor assembly and an engine control unit (ECU) 18 are further included. The temperature sensor assembly includes: a temperature sensor T1 14, disposed inside the ammonia supply rail 6, for monitoring the temperature of the medium inside the ammonia supply rail 6; a temperature sensor T2 15, disposed at the outlet of the main intake chamber 2, for monitoring the temperature of the hydrogen-ammonia mixture; a temperature sensor T3 16, disposed in the engine cylinder head cooling circuit, for monitoring the temperature of the high-temperature cooling medium; and a temperature sensor T4 17, disposed at the second coolant inlet 8 of the second flow channel system 7, for monitoring the temperature of the high-temperature cooling medium entering the second flow channel system 7. Temperature sensors T1, T2, T3, and T4 are all connected to the ECU, and the ECU is also electrically connected to a cooling circuit actuator and a relay 19. The cooling circuit actuator includes a low-temperature circuit electronic water pump, a low-temperature circuit electronic thermostat, and a high-temperature circuit electronic valve. The relay 19 is connected in series with the electric auxiliary heating element 10 to form a closed-loop active thermal management system. In other words, the sensor signal is connected to the engine control unit (ECU), and the ECU outputs control signals to the cooling circuit actuators connected to the first and second flow channel systems, as well as the drive circuit relay 19 that controls the on / off state and power of the electric auxiliary heating element 10, to form a closed-loop active thermal management system.

[0047] In a preferred embodiment of the present invention, the ECU is programmed as follows: Cold start control logic: when an engine start signal is received and the temperature sensor T3 detection value is less than a first set threshold, the relay 19 is turned on to start the electric auxiliary heating element 10, and the power of the electric auxiliary heating element 10 is adjusted by PWM pulse width modulation to keep the temperature sensor T1 detection value at 75-85°C; Hot switching control logic: when the temperature sensor T3 detection value is greater than a second set threshold, the power of the electric auxiliary heating element 10 is gradually reduced until the relay 19 is turned off, switching to heating the ammonia supply rail 6 only through the second flow channel system 7; Safe cooling control logic: when the temperature sensor T2 detection value is greater than a safe threshold, the cooling intensity of the main intake chamber 2 is enhanced.

[0048] In this invention, after the engine warms up, the coolant temperature is >70°C. The high-temperature coolant flows through the second flow channel, maintaining the ammonia rail temperature at 80-90°C. The liquid ammonia absorbs heat in the ammonia rail and completely vaporizes into a saturated gaseous state without droplets. After injection, it mixes with air and hydrogen. When the engine coolant temperature is <50°C, the ECU activates the PTC heating wire, which directly raises the ammonia rail temperature through resistance heating. Within tens of seconds (20-40 seconds), the ammonia rail temperature reaches 75-85°C, meeting the vaporization requirements. After the coolant temperature is >70°C, the heating wire is gradually turned off, switching to waste heat heating, reducing energy consumption by 80%-90%.

[0049] In a preferred embodiment of the present invention, the manifold body 1 is further integrated with a hydrogen injection port 12 and a mixing enhancement structure 13; the hydrogen injection port 12 is located downstream of the ammonia supply rail 6, and the corresponding area is wrapped by the flow channel of the first flow channel system 3; the mixing enhancement structure 13 is disposed between the hydrogen injection port 12 and the outlet of the main air inlet chamber 2, and is a venturi-type mixing throat or a flow guide swirl plate.

[0050] In this invention, the hydrogen injection port is located 20-30 mm downstream of the ammonia supply rail. The corresponding area is enclosed by the first flow channel system, maintaining a temperature of 75-80°C to prevent premature combustion of hydrogen due to high temperature. The mixing enhancement structure is a Venturi throat: a negative pressure is formed at the throat to draw in ammonia and hydrogen, and turbulence is used to break up the gas mass and improve the mixing uniformity. After gaseous ammonia is ejected from the ammonia injector, it is initially mixed with cooled air, and then enters the mixing enhancement structure together with the downstream injected hydrogen. Under the action of turbulence or swirling flow, molecular-level mixing is achieved to form a uniform mixed gas.

[0051] In a preferred embodiment of the present invention, the cold start control logic is as follows: when an engine start signal is received and the temperature sensor T3 detects a value < 50°C, the control relay 19 is turned on to start the electric auxiliary heating element 10, and the power of the electric auxiliary heating element 10 is adjusted by PWM pulse width modulation to maintain the temperature sensor T1 detects a value of 80°C; the hot switching control logic is as follows: when the temperature sensor T3 detects a value > 70°C, the power of the electric auxiliary heating element 10 is gradually reduced until the relay 19 is turned off, switching to heating the ammonia supply rail 6 only through the second flow channel system 7; the safe cooling control logic is as follows: when the temperature sensor T2 detects a value > 65°C, the cooling intensity of the main intake chamber 2 is enhanced. In the present invention, the temperature sensor T2 detects a value of 65°C as the early intervention threshold and 85°C as the absolute upper limit.

[0052] In other words, the sensor components are: T1 ammonia rail temperature, T2 air-fuel mixture temperature, T3 cylinder head coolant temperature, and T4 second flow channel inlet temperature, with a real-time sampling frequency of 10Hz for acquiring key temperature signals. ECU control logic: Cold start phase: When T3 < 50℃, start the PTC heating wire and adjust the power with PWM to make T1 = 75-85℃; at the same time, control the opening of the low temperature circuit thermostat to < 30% to avoid excessive cooling of the intake air; Warm-up stage: When 50℃≤T3≤70℃, gradually reduce the power of the heating wire and simultaneously increase the opening of the high-temperature circuit electronic valve from 30% to 100% to achieve a smooth switching of the heat source; During normal operation: When T3 > 70℃, turn off the heating element; adjust the low-temperature circuit according to T2: when T2 > 80℃, increase the speed of the electric water pump to 80%-100% to enhance cooling; when T2 < 70℃, reduce the speed of the water pump to 30%-50% to avoid a decrease in combustion efficiency; Fault protection: If the difference between T4 and T3 is greater than 10°C, it is determined that the high-temperature circuit is blocked, or if T1 is less than 60°C, the ammonia vaporization is insufficient. The ECU will trigger a fault code and limit the engine power to 50% of the rated power to avoid damage to components. Actuator control: Through the coordinated control of electronic water pump, thermostat, electronic valve and relay, the temperature regulation accuracy is achieved with a temperature control deviation of <±3℃.

[0053] In a preferred embodiment of the present invention, a turbocharged hydrogen-ammonia hybrid fuel engine is also provided, including a turbocharger, an intake system, a cylinder head, and a cylinder 20. The intake system is the intelligent thermal management hydrogen-ammonia engine intake manifold assembly with cold start electric auxiliary heating function mentioned in the present invention. The outlet of the turbocharger is connected to the inlet of the main intake chamber 2, and the outlet of the main intake chamber 2 is connected to the inlet of the cylinder 20.

[0054] In this invention, the integrated die-casting of the manifold body allows the cooling of the first flow channel and the heating of the second flow channel to share the same metal carrier. This avoids heat crosstalk between flow channels due to solid material isolation, maintains a flow channel temperature difference of 20-30°C, and improves the heat exchange efficiency of each flow channel through the high thermal conductivity of the metal. The cooling of the main intake chamber and the heating of the ammonia rail can be independently controlled. Under normal operating conditions, the engine waste heat has low energy consumption and is environmentally friendly, while cold start relies on the PTC heating wire for fast response and no delay. The two are smoothly switched by the ECU according to the coolant temperature, which solves the problem of insufficient waste heat during cold start and avoids the high energy consumption of electric auxiliary heating under normal operating conditions. While cooling the main intake chamber, the first flow channel provides a low-temperature environment of 75-80°C for the hydrogen injection interface, preventing hydrogen pre-ignition. At the same time, the turbulence-enhancing surface of the main intake chamber provides initial turbulence conditions for subsequent mixing, improving the effect of the mixing enhancement structure by 30%-40%. Cooling and mixing promote each other and jointly ensure combustion stability. In addition, the ECU synchronously adjusts the main intake chamber temperature of the cooling circuit, the ammonia rail temperature of the heating circuit, and the cold start supplementary heating of the electric auxiliary heating based on multi-sensor signals, so that each component can adapt to different operating conditions: under low load, the cooling intensity is reduced to increase the intake temperature to 75-80℃ to promote ammonia combustion; under high load, the cooling intensity is enhanced to suppress hydrogen pre-ignition; and during cold start, ammonia vaporization is prioritized—achieving closed-loop matching of operating conditions, control, and performance, with engine power fluctuation <5% and NOx emissions reduced by 30%-40% under all operating conditions.

[0055] More specific references Figure 1 As shown, the high-temperature airflow compressed by the turbocharger enters the main intake chamber. The low-temperature coolant within the honeycomb cooling channels is supplied by the low-temperature circuit inlet pipe flowing through the engine radiator, efficiently cooling it to a safe temperature. Ammonia flow: Liquid ammonia enters the integrated ammonia rail from an external supply system.

[0056] During a cold start: The ECU control unit connects the power supply to the PTC heating wire via a relay. The PTC heating wire heats up rapidly, directly heating the ammonia rail and causing the liquid ammonia to vaporize quickly.

[0057] During normal operation: The PTC heating element power is off. High-temperature coolant is supplied from the high-temperature coolant flowing through the engine and flows through the heating channel, using waste heat to continuously heat the ammonia rail.

[0058] Hydrogen and ammonia are mixed: High-pressure hydrogen is injected through the hydrogen injection port. After the gaseous ammonia is injected, it enters the Venturi mixing throat along with the hydrogen and cooled air, achieving uniform mixing at the molecular level to form an ideal mixture, which is then burned in the cylinder.

[0059] The control process is as follows: temperature sensors T1 monitor the ammonia rail temperature, T2 monitors the air-fuel mixture temperature, and T3 monitors the cylinder head coolant temperature, transmitting the signals to the ECU in real time. The ECU's built-in model performs calculations based on the engine status.

[0060] Cold start logic: If the ECU receives a start signal and T3 < 50°C, the heating element is immediately activated, and PWM control is used to maintain its power at a level that allows T1 to reach 80°C. Simultaneously, the system waits for the high-temperature coolant to heat up.

[0061] Thermal switching logic: When T3>70°C, the ECU determines that the engine has warmed up and gradually reduces the power of the PTC heating wire until it is completely turned off, switching to complete heating by high-temperature coolant.

[0062] Safety cooling logic: T2 is monitored throughout the process. If its value is close to the safety threshold such as 65°C, this threshold is the early intervention threshold, or it can be used to judge the possible intercooler failure. At the same time, it will provide feedback of high intake air temperature fault code and strong low temperature circuit cooling capacity.

[0063] This invention innovatively integrates an electric auxiliary heating system, completely solving the start-up failure problem of hydrogen-ammonia engines due to insufficient waste heat during cold starts, and achieving reliable operation throughout the entire life cycle from cold to hot engine. Through active thermal management, the high-temperature wall surface, a source of hydrogen pre-ignition, and insufficient heat, a cause of poor ammonia performance, are physically eliminated, resulting in a more thorough and reliable solution. Furthermore, the contradictory characteristics of hydrogen and ammonia are transformed into complementary advantages. The high octane rating of ammonia allows the engine to operate at high boost and high compression ratios, while this device ensures the safety of hydrogen under these high boost conditions, ultimately leading to higher engine thermal efficiency. By integrating six functions—intake manifold, intercooler auxiliary function, ammonia rail, ammonia injector heater, mixer, and cold start heater—in a single component, the system structure is greatly simplified, reducing weight, cost, and leakage risk. During normal operation, the cooling function uses the inlet water cold source, and the heating function utilizes waste heat, resulting in high energy efficiency. During cold starts, the electric auxiliary heating system responds extremely quickly. By integrating sensors and intelligent control algorithms, the intake system is transformed from a passive component into an actively adjustable intelligent organ, capable of adapting to various complex operating conditions, providing a new control dimension for optimizing combustion and controlling emissions.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An intake system for a turbocharged hydrogen-ammonia hybrid fuel engine, comprising a manifold body (1), characterized in that, The manifold body (1) integrates the following: The main intake chamber (2) is used to circulate pressurized air and a mixture of hydrogen and ammonia. The first flow channel system (3) encloses the main intake chamber (2). The first coolant inlet (4) and the first coolant outlet (5) of the first flow channel system (3) are respectively connected to the engine low-temperature cooling circuit for circulating low-temperature cooling medium to actively cool the main intake chamber (2). Ammonia supply rail (6) is used to transport liquid ammonia; The second flow channel system (7) is used to wrap the ammonia supply rail (6). The second coolant inlet (8) and the second coolant outlet (9) of the second flow channel system (7) are respectively connected to the engine high-temperature cooling circuit for circulating high-temperature cooling medium to actively heat the ammonia supply rail (6). An electric auxiliary heating element (10) is embedded in the wall of the ammonia supply rail (6) or between the wall of the ammonia supply rail (6) and the second flow channel system (7) to assist in heating the ammonia supply rail (6) during cold start.

2. The intake system according to claim 1, characterized in that, The electric auxiliary heating element (10) is a PTC heating wire, which is uniformly arranged along the length of the ammonia supply rail (6). The first flow channel system (3) and the second flow channel system (7) are isolated by the solid material of the manifold body (1).

3. The intake system according to claim 1, characterized in that, It also includes a temperature sensor assembly and an engine control unit (ECU) (18); the temperature sensor assembly includes: a temperature sensor T1 (14), which is located inside the ammonia supply rail (6) and is used to monitor the temperature of the medium inside the ammonia supply rail (6); a temperature sensor T2 (15), which is located at the outlet of the main intake chamber (2) and is used to monitor the temperature of the hydrogen-ammonia mixture; a temperature sensor T3 (16), which is located in the engine cylinder head cooling circuit and is used to monitor the temperature of the high-temperature cooling medium; and a temperature sensor T4 (17), which is located at the coolant inlet (8) of the second flow channel system (7) and is used to monitor the temperature of the high-temperature cooling medium entering the second flow channel system (7); The temperature sensor assembly is connected to the engine control unit (ECU) (18). The engine control unit (ECU) (18) is also electrically connected to a cooling circuit actuator and a relay (19). The cooling circuit actuator includes a low-temperature circuit electronic water pump, a low-temperature circuit electronic thermostat, and a high-temperature circuit electronic valve. The relay (19) is connected in series with the electric auxiliary heating element (10) to form a closed-loop active thermal management system.

4. The intake system according to claim 1, characterized in that, The engine control unit (ECU) (18) is programmed as follows: Cold start control logic: When the engine start signal is received and the temperature sensor T3 (16) detects a value less than the first set threshold, the electric auxiliary heating element (10) is started, and the power of the electric auxiliary heating element (10) is adjusted by PWM pulse width modulation so that the temperature sensor T1 (14) detects a value of 75-85℃; Hot switching control logic: When the temperature sensor T3 (16) detects a value greater than the second set threshold, the power of the electric auxiliary heating element (10) is gradually reduced until the relay (19) is disconnected, and the system switches to heating the ammonia supply rail (6) only through the second flow channel system (7); Safe cooling control logic: When the temperature sensor T2 (15) detects a value greater than the safe threshold, the cooling intensity of the main intake chamber (2) is increased.

5. The intake system according to claim 4, characterized in that, The manifold body (1) also integrates a hydrogen injection port (12), an ammonia injector mounting base (11), and a mixing enhancement structure (13); the hydrogen injection port (12) is located downstream of the ammonia supply rail (6), and the corresponding area is wrapped by the flow channel of the first flow channel system (3); the mixing enhancement structure (13) is located between the hydrogen injection port (12) and the outlet of the main air inlet chamber (2), and is a venturi tube type mixing throat or a flow guide swirl plate; the ammonia injector mounting base (11) is located upstream of the hydrogen injection port (12).

6. The intake system according to claim 1, characterized in that, The flow channel of the first flow channel system (3) tightly wraps the main air intake chamber (2) with a three-dimensional honeycomb mesh structure, and the flow channel of the second flow channel system (7) tightly wraps the ammonia supply rail (6) with a double-layer spiral coil structure.

7. The intake system according to claim 1, characterized in that, The inner wall surface of the main air intake chamber (2) is a turbulence-enhanced surface.

8. The intake system according to claim 4, characterized in that, The cold start control logic is as follows: when the engine start signal is received and the temperature sensor T3 (16) detects a value of < 50°C, the control relay (19) is turned on, the electric auxiliary heating element (10) is started, and the power of the electric auxiliary heating element (10) is adjusted by PWM pulse width modulation so that the temperature sensor T1 (14) detects a value of 80°C; the hot switching control logic is as follows: when the temperature sensor T3 (16) detects a value of > 70°C, the power of the electric auxiliary heating element (10) is gradually reduced until the relay (19) is turned off, and the switch is made to heat the ammonia supply rail (6) only through the second flow channel system (7); the safety cooling control logic is as follows: when the temperature sensor T2 (15) detects a value of > 65°C, the cooling intensity of the main intake chamber (2) is enhanced.

9. A turbocharged hydrogen-ammonia hybrid fuel engine, comprising a turbocharger, an intake system, a cylinder head, and a cylinder (20), characterized in that, The intake system is the intake system according to any one of claims 1-8, the outlet of the turbocharger is connected to the inlet of the main intake chamber (2), and the outlet of the main intake chamber (2) is connected to the inlet of the cylinder (20).

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