Control device and control method for intake air temperature of ammonia engine

Abstract

The present invention provides an ammonia engine intake temperature control device and method, belonging to the field of engine control technology. The device includes: an intercooler, whose output end is connected to the input end of a liquid ammonia cylinder, and a first valve is provided in a branch of the intercooler; a second valve is provided in an intercooler bypass branch; an EGR cooler, whose input end is connected to the output end of the liquid ammonia cylinder via a fifth valve, and whose output end is connected to the input end of the liquid ammonia cylinder, and a third valve is provided in a branch of the EGR cooler; a fourth valve is provided in the EGR bypass branch; and a controller for controlling the first, third, and fifth valves to close, the second valve to open, and adjusting the opening of the fourth valve based on an intake temperature target value during cold start and low load conditions. The present invention can solve the technical problem of existing ammonia engines that suffer from low temperatures due to the latent heat of vaporization of liquid ammonia when using liquid ammonia fuel for intake port injection or direct injection in low-temperature environments.

Description

Technical Field

[0001] The present invention relates to the technical field of engine control, and in particular to a device and method for controlling the intake air temperature of an ammonia engine. Background Art

[0002] In the context of carbon neutrality, ammonia, a 100% renewable, zero-carbon fuel, can power ships, trucks, and construction vehicles, offering significant potential in the transition from fossil fuels to zero-carbon fuels. Ammonia is a readily liquefiable gas. When cooled to -33.4°C at ambient pressure or pressurized to 7-8 atmospheres at room temperature, it liquefies into a colorless liquid. Ammonia's ease of liquefaction and zero carbon content make it ideal as a fuel for internal combustion engines. Liquid ammonia has a high latent heat of vaporization of 1371 kJ / kg, compared to 375 kJ / kg for diesel. Therefore, when using liquid ammonia as a fuel, its higher latent heat of vaporization can lead to excessively low intake and cylinder temperatures, resulting in incomplete vaporization and wall wetting. This can also lead to uneven mixture mixing, poor combustion, and reduced efficiency. Furthermore, it can cause difficulties with cold starts and poor responsiveness under acceleration conditions.

[0003] For engines equipped with an EGR (Exhaust Gas Recirculation) system, the primary function of the EGR system cooler is to reduce the temperature of exhaust gas flowing back from the exhaust system to the intake system. This is because during engine operation, some of the burned exhaust gas is reintroduced into the intake system, mixed with fresh air, and then re-entered the cylinder for combustion. However, this exhaust gas is typically at a high temperature. If not cooled, it may cause excessive thermal loads on components such as the engine's intake system, cylinder walls, and pistons, affecting engine performance and life.

[0004] When an engine uses turbocharging or supercharging technology, the supercharger (compressor) significantly increases intake air pressure, but this also increases intake air temperature. High-temperature air reduces air density, which in turn affects the engine's charging efficiency. An intercooler cools the supercharged air, reducing its temperature and increasing intake air density, allowing the engine to inhale more dense air.

[0005] However, during engine operation, due to the complexity of the operating conditions, it is sometimes necessary to adjust the cooling effect of the intake system to adapt to different needs. For example, when the engine is running in a cold environment with low load, especially during cold start and the initial stage after cold start, due to the low EGR rate and relatively low exhaust temperature under natural conditions, if the same cooling strategy as the high-load operating condition is adopted at this time, that is, all exhaust gases in the EGR branch are allowed to flow through the EGR cooler for cooling, it may cause the exhaust gas to have an abnormally low temperature when it flows out of the EGR module. Similarly, due to the low external ambient temperature, if the pressurized air is still cooled through the intercooler at this time, it may cause the intake temperature to be too low, thereby affecting the cold start performance of the engine and having an adverse effect on engine performance.

[0006] In addition, under low temperature and low load conditions, the engine's thermal efficiency may be affected. Proper intake air temperature can enable the engine to reach normal operating temperature faster, thereby improving thermal efficiency. It also helps improve the atomization effect of the fuel, promotes the complete combustion of the fuel, and further improves engine performance.

[0007] Inappropriate EGR cooling and intercooling strategies in low-temperature environments may cause a series of problems, including intake air icing, increased blockage risk, and accelerated material aging, which may ultimately have an adverse effect on vehicle dynamics.

[0008] In summary, when existing ammonia engines use liquid ammonia fuel for intake port injection or direct injection in low-temperature environments, there is a problem of low temperature caused by the latent heat of vaporization of liquid ammonia, which in turn leads to problems such as intake icing, increased risk of blockage, and accelerated material aging in the ammonia engine. Summary of the Invention

[0009] In view of this, it is necessary to provide a control device and method for the intake temperature of an ammonia engine to solve the technical problem that when the existing ammonia engine uses liquid ammonia fuel for intake injection or direct injection in a low temperature environment, the latent heat of liquid ammonia vaporization causes the temperature to be low.

[0010] In order to solve the above problems, the present invention provides, on the one hand, a device for controlling the intake air temperature of an ammonia engine, comprising:

[0011] An intercooler, the input end of which is connected to the compressor, the output end of which is connected to the input end of the liquid ammonia cylinder, and a first valve is provided on the branch where the intercooler is located;

[0012] An intercooler bypass branch, the input end of which is connected to the compressor, and the output end of which is connected to the input end of the liquid ammonia cylinder, and a second valve is provided on the intercooler bypass branch;

[0013] The EGR cooler has an input end connected to the output end of the liquid ammonia cylinder through a fifth valve, and an output end connected to the input end of the liquid ammonia cylinder, and a third valve is provided on the branch where the EGR cooler is located;

[0014] An EGR bypass branch, the input end of which is connected to the output end of the liquid ammonia cylinder, the output end of which is connected to the input end of the liquid ammonia cylinder, and a fourth valve is provided on the EGR bypass branch;

[0015] The controller is used to control the first valve, the third valve and the fifth valve to close, the second valve to open, and adjust the opening of the fourth valve based on the intake air temperature target value under cold start and low load conditions.

[0016] In a possible implementation, the first valve and the second valve are two independent valves, or constitute a three-way butterfly valve.

[0017] In a possible implementation, the third valve and the fourth valve are two independent valves, or constitute a three-way butterfly valve.

[0018] In a possible implementation, the controller is further configured to determine the required mass of liquid ammonia fuel based on the operating conditions of the ammonia engine.

[0019] In one possible implementation, the controller is configured to determine the energy required for vaporizing the liquid ammonia based on the required mass of liquid ammonia fuel, and to determine a target intake temperature of the ammonia engine based on a target intake air volume of the ammonia engine, a temperature drop of the target intake air volume due to vaporization of the liquid ammonia, and the energy required for vaporization of the liquid ammonia.

[0020] In a possible implementation, the controller is configured to adjust the opening of the fourth valve using a PID control strategy based on a target intake air temperature of the ammonia engine and a real-time opening of the fourth valve.

[0021] In one possible implementation, the controller is further configured to control the third valve and the fifth valve to open and the fourth valve to close under medium and high load conditions, and to determine the openings of the first valve and the second valve based on a target intake temperature of the ammonia engine.

[0022] In one possible implementation, the controller is further configured to adjust the openings of the first valve and the second valve using a PID control strategy based on a target intake temperature of the ammonia engine and the real-time openings of the first valve and the second valve.

[0023] On the other hand, the present invention further provides a method for controlling the intake air temperature of an ammonia engine, the control method being applied to any of the control devices described above, the control method comprising:

[0024] The controller controls the first valve, the third valve and the fifth valve to be closed, and controls the second valve to be open under cold start and low load conditions;

[0025] The controller adjusts the opening of the fourth valve based on the intake air temperature target value.

[0026] In one possible implementation, the method for controlling the intake air temperature of an ammonia engine further includes:

[0027] The controller controls the third valve and the fifth valve to open and the fourth valve to close under medium and high load conditions, and determines the openings of the first valve and the second valve based on a target intake air temperature of the ammonia engine.

[0028] The beneficial effects of adopting the above implementation are as follows: the control device and control method of the intake air temperature of the ammonia engine provided by the present invention are provided by arranging a first valve at the output end of the intercooler, a second valve on the intercooler bypass branch, a fifth valve on the input end of the EGR cooler, a third valve on the output end of the EGR cooler, and a fourth valve on the EGR bypass branch, and determining the intake air temperature target value of the ammonia engine based on the required liquid ammonia fuel quality through a controller, and controlling the first valve, the third valve and the fifth valve to be closed under cold start and low load conditions, and controlling the second valve to be closed. Open, and adjust the opening of the fourth valve based on the intake air temperature target value, so as to achieve the cooling strategy of the EGR system and the intercooler system under low load conditions in cold environments, reduce the amount of exhaust gas flowing through the EGR cooler or reduce the cooling efficiency of the cooler to ensure that the exhaust gas maintains an appropriate temperature when flowing out of the EGR module, and through the intercooler bypass, the pressurized air can bypass the intercooler and directly enter the engine, thereby solving the technical problem that when the existing ammonia engine uses liquid ammonia fuel for intake port injection or direct injection in a low temperature environment, the latent heat of liquid ammonia vaporization causes the temperature to be low. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 A schematic structural diagram of a first embodiment of a device for controlling the intake air temperature of an ammonia engine provided by the present invention;

[0031] Figure 2 A schematic structural diagram of a second embodiment of the control device for the intake air temperature of an ammonia engine provided by the present invention;

[0032] Figure 3A schematic structural diagram of a third embodiment of the control device for the intake air temperature of an ammonia engine provided by the present invention;

[0033] Figure 4 A schematic structural diagram of a fourth embodiment of the control device for the intake air temperature of an ammonia engine provided by the present invention;

[0034] Figure 5 A schematic structural diagram of a fifth embodiment of the control device for the intake air temperature of an ammonia engine provided by the present invention;

[0035] Figure 6 A schematic structural diagram of a sixth embodiment of the device for controlling the intake air temperature of an ammonia engine provided by the present invention;

[0036] Figure 7 A flow chart of an embodiment of a method for controlling the intake air temperature of an ammonia engine provided by the present invention;

[0037] Figure 8 This is a flow chart of another embodiment of the method for controlling the intake air temperature of an ammonia engine provided by the present invention. DETAILED DESCRIPTION

[0038] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0039] In the description of the embodiments of the present application, unless otherwise specified, “a plurality of” means two or more.

[0040] The terms "including" and "having" and any variations thereof in the embodiments of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or device comprising a series of steps or modules is not necessarily limited to those steps or modules explicitly listed, but may include other steps or modules not explicitly listed or inherent to these processes, methods, products or devices.

[0041] The naming or numbering of the steps in the embodiments of the present invention does not mean that the steps in the method flow must be executed in the time / logical sequence indicated by the naming or numbering. The execution order of the named or numbered process steps can be changed according to the technical purpose to be achieved, as long as the same or similar technical effects can be achieved.

[0042] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0043] The present invention provides a device and method for controlling the intake air temperature of an ammonia engine, which are described below respectively.

[0044] like Figure 1 As shown, the present invention provides a device for controlling the intake temperature of an ammonia engine, comprising:

[0045] An intercooler, the input end of which is connected to the compressor, the output end of which is connected to the input end of the liquid ammonia cylinder, and a first valve is provided on the branch where the intercooler is located;

[0046] An intercooler bypass branch, the input end of which is connected to the compressor, and the output end of which is connected to the input end of the liquid ammonia cylinder, and a second valve is provided on the intercooler bypass branch;

[0047] An EGR (Exhaust Gas Recirculation) cooler, the input end of which is connected to the output end of the liquid ammonia cylinder via a fifth valve, and the output end of which is connected to the input end of the liquid ammonia cylinder, and a third valve is provided on the branch where the EGR cooler is located;

[0048] An EGR bypass branch, the input end of which is connected to the output end of the liquid ammonia cylinder, the output end of which is connected to the input end of the liquid ammonia cylinder, and a fourth valve is provided on the EGR bypass branch;

[0049] The controller is used to control the first valve, the third valve and the fifth valve to close, and the second valve to open under cold start and low load conditions, and adjust the opening of the fourth valve based on the intake air temperature target value to adjust the actual intake air temperature value to the intake air temperature target value.

[0050] It is understood that the controller can be an engine control unit (ECU) or a vehicle control unit (VCU). The first valve is the intercooler rear valve S1, the second valve is the intercooler bypass valve S2, the third valve is the EGR cooler rear valve S3, the fourth valve is the EGR bypass valve S4, and the fifth valve is the EGR valve.

[0051] Figure 1 The figure shows the structure of the control device for the intake temperature of an ammonia engine corresponding to the direct injection of liquid ammonia into the cylinder. In another embodiment, the present invention also provides Figure 2 The structure diagram of the control device of the ammonia engine intake temperature corresponding to the liquid ammonia intake port injection is shown.

[0052] The intake air temperature control device for an ammonia engine provided by this invention is designed to optimize intake air temperature and efficiency during low-temperature cold start and low-load engine conditions. This device precisely controls the exhaust gas temperature and flow rate entering the intake manifold by allowing a portion of the exhaust gas to pass through the EGR cooler for cooling before passing through the EGR valve (fifth valve), while another portion bypasses the EGR cooler through a bypass branch. The two portions are then mixed upstream and downstream of the EGR cooler using two-way or three-way butterfly valves. Similarly, this solution precisely controls the temperature and flow rate of the supercharged gas entering the intake manifold by allowing a portion of the supercharged gas to pass through the intercooler for cooling before passing through the throttle, while another portion bypasses the intercooler through a bypass branch and is mixed downstream of the intercooler using a three-way butterfly valve. The combined action of these two mechanisms achieves precise control of the overall engine intake air temperature and flow rate.

[0053] The device for controlling the intake air temperature of an ammonia engine provided by the present invention comprises:

[0054] 1) EGR cooler: Responsible for cooling part of the exhaust gas discharged from the engine, lowering its temperature to reduce the generation of nitrogen oxides (NOx).

[0055] 2) EGR bypass branch: provides a channel for uncooled exhaust gas to bypass the EGR cooler.

[0056] 3) Intercooler: Responsible for cooling the high-temperature and high-pressure gas from the supercharger, reducing its density and increasing the engine's air intake.

[0057] 4) Intercooler bypass branch: provides a channel for uncooled pressurized gas to bypass the intercooler.

[0058] 5) Three-way butterfly valves consisting of the first and second valves, and the third and fourth valves: These are installed downstream and upstream of the EGR cooler and intercooler, respectively. They are divided into two chambers: one for adjusting the mixture ratio of cooled and uncooled exhaust gas, and the other for adjusting the mixture ratio of cooled and uncooled boost gas. The degree of opening of the butterfly valve determines the mixture ratio of the hot and cold gases. Features of two-way butterfly valves include: the valve body is made of corrosion-resistant, high-temperature materials to withstand the high-temperature and high-pressure environments of exhaust and boost gas. The butterfly disc, as the control element, rotates to adjust the opening of the channel, thereby regulating the exhaust gas flow. The edge of the butterfly disc is typically specially treated to reduce fluid resistance and improve sealing performance. A sealing ring or gasket is placed between the butterfly disc and the valve seat to effectively prevent exhaust gas leakage when closed. The butterfly valve's actuator (e.g., electric, pneumatic, or hydraulic) receives signals from the engine control unit (ECU) to precisely control the rotation angle of the butterfly disc, achieving precise regulation of exhaust flow.

[0059] 6) EGR valve: Located after the three-way butterfly valve, it controls the amount of mixed exhaust gas entering the intake manifold.

[0060] 7) Throttle: Located after the three-way butterfly valve, it controls the amount of mixed pressurized gas entering the intake manifold.

[0061] The three-way butterfly valve used in this invention consists of a valve body, a drive shaft, three valve discs (valve disc 1, valve disc 2, and valve disc 3), a motor, and a cooling water jacket within the valve body. The valve body features three independent airflow channels, each corresponding to a valve disc. The valve discs are connected to the motor via a drive shaft for synchronous control. Valve discs 2 and 3 have the same phase angle, but are 90° out of phase with valve disc 1. This ensures that, by default, the valve disc in channel 1 is fully open, while the valve discs in channels 2 and 3 are fully closed.

[0062] The key technologies and innovations of the present invention include:

[0063] Single drive shaft control: One drive shaft is used to simultaneously control the opening and closing of three valve plates, driven by a single motor, which simplifies the structure, reduces costs and improves reliability.

[0064] Cooling channel design: A cooling water jacket is provided inside the valve body. By circulating cooling water, the high-temperature gas flowing through the valve body is cooled or the low-temperature gas is kept warm, thus expanding the application range of the valve.

[0065] Flexible opening adjustment: Through the precise control of the motor, all valves can be adjusted to any opening between fully closed and fully open, including half-open state, to meet the gas flow requirements under different working conditions.

[0066] Variable channel diameter: According to actual usage, channels of different diameters can be selected to optimize gas flow resistance and improve throttling efficiency.

[0067] In some embodiments, the first valve and the second valve are two independent valves, or constitute a three-way butterfly valve.

[0068] The third valve and the fourth valve are two independent valves, or constitute a three-way butterfly valve.

[0069] It is understandable that if Figure 3 、 Figure 4 、 Figure 5 and Figure 6 As shown, the first valve S1 and the second valve S2 of the present invention can constitute a three-way butterfly valve S12, and the third valve S3 and the fourth valve S4 can also constitute a three-way butterfly valve S34.

[0070] The highly integrated and compact design of a three-way butterfly valve allows for easier integration with other system components (such as the EGR cooler, EGR valve, and intercooler), significantly reducing the length and complexity of the bypass line. This not only saves valuable engine compartment space but also reduces the difficulty and cost of piping layout. This high level of integration not only reduces system complexity but also improves overall system reliability and maintainability. By tightly integrating the three-way butterfly valve with the EGR cooler and intercooler circuits, a fully functional and compact integrated module is formed. This modular design simplifies installation and improves overall system performance and reliability. It also facilitates subsequent maintenance and replacement, as the entire module can be disassembled and assembled as a single unit.

[0071] While two traditional solenoid valves can function in an EGR bypass system, their size and shape may limit tight integration with other components, impacting the overall system layout and efficiency. Traditional solenoid valves may require additional piping and fittings to connect the EGR cooler and EGR valve, increasing system complexity and footprint. The typically loose connection between traditional solenoid valves and the EGR cooler makes it difficult to achieve a high degree of modularity. This can lead to increased time and labor required during installation, maintenance, and replacement.

[0072] In addition, the three-way butterfly valve has better flow regulation performance and can more accurately control the mixing ratio of hot and cold gases in different air chambers and the amount of exhaust gas recirculation. Simple structure, high reliability, and reduced cost: The design of one drive shaft controlling three valve plates greatly simplifies the structure, improves the reliability and stability of the system, and reduces manufacturing costs compared to the traditional method of independent control of multiple valve plates. Wide range of applications: The integrated cooling function enables the throttle valve to handle high-temperature and low-temperature gases at the same time, broadening its scope of application. Low gas flow resistance: By adjusting the channel diameter and the valve plate opening, precise control of gas flow resistance can be achieved, thereby improving throttling efficiency.

[0073] This is crucial for optimizing engine performance and reducing emissions. The exhaust gas in the EGR system is hot and may contain corrosive substances. The three-way butterfly valve is usually made of high-temperature and corrosion-resistant materials to ensure long-term stable operation.

[0074] In some embodiments, the controller is further configured to determine a required mass of liquid ammonia fuel based on operating conditions of the ammonia engine.

[0075] In some embodiments, the controller is configured to determine the energy required for vaporizing the liquid ammonia based on the required liquid ammonia fuel mass, and to determine a target intake air temperature of the ammonia engine based on a target intake air volume of the ammonia engine, a temperature drop of the target intake air volume due to vaporization of the liquid ammonia, and the energy required for vaporization of the liquid ammonia.

[0076] In some embodiments, the controller is configured to adjust the opening of the fourth valve using a PID control strategy based on a target intake air temperature of the ammonia engine and a real-time opening of the fourth valve.

[0077] In some embodiments, the controller is further configured to control the third valve and the fifth valve to open and the fourth valve to close under medium and high load conditions, and to determine the openings of the first valve and the second valve based on a target intake temperature of the ammonia engine.

[0078] In some embodiments, the controller is further configured to adjust the openings of the first valve and the second valve using a PID (proportional, integral, derivative) control strategy based on a target intake temperature of the ammonia engine and the real-time openings of the first valve and the second valve.

[0079] In one embodiment, the working process of the device for controlling the intake air temperature of an ammonia engine provided by the present invention includes:

[0080] 1) Exhaust gas diversion: The exhaust gas discharged from the engine is divided into two paths at a specific location, one path enters the EGR cooler, and the other path passes through the bypass branch.

[0081] 2) Compressed gas diversion: The air after being pressurized by the supercharger is divided into two paths at a specific position, one path enters the intercooler, and the other path passes through the bypass branch.

[0082] 3) Exhaust gas cooling: The exhaust gas entering the EGR cooler exchanges heat with the coolant through the cooling pipe, and the temperature is significantly reduced.

[0083] 4) Charged gas cooling: The charged gas entering the intercooler exchanges heat with the external environment through the cooling channel, and the temperature is significantly reduced.

[0084] 5) Mixing of hot and cold exhaust gases: Cooled and uncooled exhaust gases are mixed at the outlet of the three-way butterfly valve downstream of the EGR cooler. The opening of the butterfly valve is adjusted according to engine operating conditions and emission requirements to optimize the mixing ratio.

[0085] 6) Mixing of hot and cold supercharged gases: Cooled supercharged gases and uncooled supercharged gases are mixed at the outlet of the three-way butterfly valve. The opening of the butterfly valve is adjusted according to the engine operating conditions and ambient temperature to optimize the mixing ratio.

[0086] 7) Exhaust Gas Recirculation: Mixed exhaust gas enters the intake manifold through the EGR valve, where it mixes with fresh air and re-enters the combustion chamber. The EGR valve opening is adjusted in real time by the engine control unit (ECU) based on engine speed, load, temperature, and other parameters to control the amount of exhaust gas recirculated.

[0087] 8) Engine intake: After the temperature is adjusted by the three-way butterfly valve, the supercharged mixture and the exhaust gas mixture are respectively regulated by the throttle valve and the EGR valve to enter the engine intake manifold, and finally enter the cylinder for combustion and work.

[0088] In another embodiment, the structure of the control device for the intake air temperature of an ammonia engine provided by the present invention is as follows: Figure 1 and Figure 2 As shown in the figure, compared with the traditional diesel engine, an intercooler rear valve S1 (first valve), an intercooler bypass line and its corresponding intercooler bypass valve S2 (second valve) are added, and an EGR cooler rear valve S3 (third valve) and an EGR bypass line and its corresponding EGR bypass valve S4 (fourth valve) are added. Figure 3 、 Figure 4 、 Figure 5 and Figure 6 As shown, S1 and S2 can be used as two adjustable opening valves set on the intercooler and its bypass pipelines, or as a three-way adjustable opening valve S12 after the two pipelines are merged. Similarly, S3 and S4 can be used as two adjustable opening valves set on the EGR cooler and its bypass pipelines, or as a three-way adjustable opening valve S34 after the two pipelines are merged.

[0089] The present invention is not limited to the use of a single three-way butterfly valve or two separate butterfly valves, nor is it limited to the placement of the three-way butterfly valve upstream or downstream of the intercooler / EGR cooler. Furthermore, the present invention is not limited to whether ammonia is injected into the intake port or directly into the cylinder, as long as the same function is achieved.

[0090] The control device for the intake air temperature of an ammonia engine provided by the present invention has the following beneficial effects:

[0091] Reduce intercooler energy consumption: The intercooler bypass structure is adopted to reduce the energy consumption requirements of the intercooler, allowing the use of smaller fans and coolers.

[0092] Optimize the combustion process: Increase the intake air temperature to make the liquid ammonia vaporize more fully, the mixture mix more evenly, and reduce the risk of wall wetting; at the same time, increase the intake air temperature to increase the combustion temperature, increase the combustion speed, and achieve better combustion effect.

[0093] Optimizing Engine Performance: While maintaining low emissions, the engine's combustion process is optimized by adjusting the exhaust gas recirculation rate, improving fuel economy and power performance. During low engine load or cold start phases, exhaust gas temperatures are low. If all exhaust gas passes through the EGR cooler or intercooler, the gas temperature may be too low, leading to ice formation or blockage in the intake system. The three-way butterfly valve increases the flow rate of the bypass branch, reducing the proportion of low-temperature gas and preventing the cooling medium from remaining in the heat exchanger for a long time, thereby reducing the risk of ice or freezing and protecting component safety. Furthermore, by regulating the temperature of the mixed gas, the three-way butterfly valve indirectly affects the temperature and heat capacity of the mixed gas entering the cylinder, thereby helping to optimize the combustion process and improve the engine's fuel economy and emissions performance.

[0094] Enhanced system flexibility: This technical solution allows flexible adjustment of intake and exhaust gas treatment strategies according to different engine operating conditions and emission requirements.

[0095] The present invention also provides a method for controlling the intake temperature of an ammonia engine, which is applied to the above-mentioned control device, such as Figure 7 As shown, the control method includes:

[0096] S701, under cold start and low load conditions, the controller controls the first valve, the third valve, and the fifth valve to close, and controls the second valve to open;

[0097] S702: The controller adjusts the opening of the fourth valve based on the target intake air temperature.

[0098] In some embodiments, the method for controlling the intake air temperature of an ammonia engine further includes:

[0099] The controller controls the third valve and the fifth valve to open and the fourth valve to close under medium and high load conditions, and determines the openings of the first valve and the second valve based on a target intake air temperature of the ammonia engine.

[0100] In some embodiments, the present invention provides a method for controlling the intake temperature of an ammonia engine, such as Figure 8 As shown, including:

[0101] Working condition judgment:

[0102] First, the ECU identifies the engine throttle and speed signals to determine whether the engine is operating under cold start and low load conditions or medium and high load conditions.

[0103] Determine target parameters:

[0104] Determine the required liquid ammonia fuel mass M based on engine operating conditions (such as speed and load), and calculate the energy E required for liquid ammonia vaporization. Based on current engine test experience, determine the target engine intake air volume V1 and target intake air temperature T3. The target intake air temperature drop due to liquid ammonia vaporization is reversely deduced from E, V1, and T3. The target intake air temperature T3 is a function of the liquid ammonia mass: T3 = f(M). This determines the openings of the intercooler valve S1, intercooler bypass valve S2, EGR valve S5, EGR cooling valve S3, and EGR bypass valve S4.

[0105] Load judgment:

[0106] Under cold start and low load conditions, close the intercooler valve S1, fully open the intercooler bypass valve S2 (the corresponding opening of S12 can be the same), close the EGR valve S5 and the EGR cooling valve S3, and based on the mixed temperature T 06 Determine the opening K4 of the EGR cooling bypass valve S4 to prevent the engine from being affected by cold start and low load operation due to low ambient temperature.

[0107] Under medium and high load conditions, the EGR cooling valve S3 and the EGR valve S5 are fully opened, the EGR cooling bypass S4 is fully closed, and the opening K2 of the intercooler bypass S2 and the opening K1 of the intercooler valve S1 are adjusted based on the target intake air temperature T3.

[0108] Inlet air temperature model:

[0109] Using one-dimensional / three-dimensional simulation calculation results and relevant test data, a mathematical relationship T3=f(S1, S2, S3, S4) between the target engine intake temperature and the two-way / three-way butterfly valve opening (i.e., the degree of EGR cooler bypass / intercooler bypass) under different operating conditions was constructed. The accurate engine intake temperature was estimated using existing sensor data and hardware status.

[0110] Intercooler bypass control:

[0111] The target intercooler after-temperature T1 is achieved by the opening of the two-way / three-way butterfly valve.

[0112] EGR valve opening judgment:

[0113] Detect whether the engine has an EGR valve opening requirement under the current operating conditions. At medium and high loads, the EGR valve is opened and needs to enter a closed-loop control strategy with T3 as the control target based on the target value of the mixed intake temperature T3.

[0114] Intercooler bypass & EGR cooler bypass control (closed loop control B):

[0115] The target intake air temperature T3 is achieved by the opening of the two-way / three-way butterfly valve, PID parameters: CURVE intake air temperature T3 = f(S1, S2, S3, S4).

[0116] Continuous monitoring and adjustment:

[0117] During the entire process, the system will continuously monitor key parameters such as ambient temperature, intake temperature, intercooler temperature, and EGR cooler temperature, and dynamically adjust the intercooler valve opening, intercooler bypass opening, EGR cooling valve opening, EGR cooling bypass valve opening, and EGR valve opening as needed to ensure that the engine can achieve cold start and stable combustion under various operating conditions, and achieve optimal fuel economy and emission performance.

[0118] The above is a detailed introduction to the control device and control method for the intake air temperature of an ammonia engine provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A control device for the intake air temperature of an ammonia engine, characterized in that: include: An intercooler, the input end of which is connected to the compressor, the output end of which is connected to the input end of the liquid ammonia cylinder, and a first valve is provided on the branch where the intercooler is located; An intercooler bypass branch, the input end of which is connected to the compressor, and the output end of which is connected to the input end of the liquid ammonia cylinder, and a second valve is provided on the intercooler bypass branch; The EGR cooler has an input end connected to the output end of the liquid ammonia cylinder through a fifth valve, and an output end connected to the input end of the liquid ammonia cylinder, and a third valve is provided on the branch where the EGR cooler is located; An EGR bypass branch, the input end of which is connected to the output end of the liquid ammonia cylinder, the output end of which is connected to the input end of the liquid ammonia cylinder, and a fourth valve is provided on the EGR bypass branch; The controller is used to control the first valve, the third valve and the fifth valve to close, the second valve to open, and adjust the opening of the fourth valve based on the intake air temperature target value under cold start and low load conditions.

2. The control device for the intake air temperature of an ammonia engine according to claim 1, characterized in that: The first valve and the second valve are two independent valves, or constitute a three-way butterfly valve.

3. The control device for the intake air temperature of an ammonia engine according to claim 1, characterized in that: The third valve and the fourth valve are two independent valves, or constitute a three-way butterfly valve.

4. The control device for the intake air temperature of an ammonia engine according to claim 1, characterized in that: The controller is further configured to determine the required liquid ammonia fuel mass based on the operating conditions of the ammonia engine.

5. The control device for the intake air temperature of an ammonia engine according to claim 1, characterized in that: The controller is configured to determine the energy required for vaporizing the liquid ammonia based on the required mass of the liquid ammonia fuel, and to determine a target intake air temperature of the ammonia engine based on the target intake air volume of the ammonia engine, the temperature drop of the target intake air volume due to vaporization of the liquid ammonia, and the energy required for vaporization of the liquid ammonia.

6. The control device for the intake air temperature of an ammonia engine according to claim 1, characterized in that: The controller is used to adjust the opening of the fourth valve by adopting a PID control strategy based on the target value of the intake air temperature of the ammonia engine and the real-time opening of the fourth valve.

7. The control device for the intake air temperature of an ammonia engine according to any one of claims 1 to 6, characterized in that: The controller is further configured to control the third valve and the fifth valve to open and the fourth valve to close under medium and high load conditions, and to determine the openings of the first valve and the second valve based on a target intake air temperature of the ammonia engine.

8. The control device for the intake air temperature of an ammonia engine according to claim 7, characterized in that: The controller is further configured to adjust the openings of the first valve and the second valve using a PID control strategy based on a target intake temperature of the ammonia engine and the real-time openings of the first valve and the second valve.

9. A method for controlling the intake air temperature of an ammonia engine, characterized in that: The control method is applied to the control device according to any one of claims 1 to 8, and the control method includes: The controller controls the first valve, the third valve and the fifth valve to be closed, and controls the second valve to be open under cold start and low load conditions; The controller adjusts the opening of the fourth valve based on the intake air temperature target value.

10. The method for controlling the intake air temperature of an ammonia engine according to claim 9, characterized in that: Also includes: The controller controls the third valve and the fifth valve to open and the fourth valve to close under medium and high load conditions, and determines the openings of the first valve and the second valve based on a target intake air temperature of the ammonia engine.

Images