Control method based on low-temperature cold start of inspiration integrated heavy oil engine

Abstract

The invention relates to a control method based on low-temperature cold start of a heuristic integrated heavy oil engine, and relates to the field of heuristic integrated heavy oil engines. According to the technical scheme, the preheating plug in the cylinder is combined with the air inlet heating grid, synchronous control is achieved through the same relay, the electric energy requirements of synchronous work and dragging and preheating are met by means of sufficient battery capacity, and the device can be adapted to the ultra-low temperature of-40 DEG C or below and the plateau environment of 4700 m or above; three starting attempts are supported by single-time power-on through intelligent preheating control logic, the pre-preheating and heating-while-dragging processes are executed each time, fault information is automatically uploaded after starting fails, frequent power-off is not needed, and the starting efficiency is improved. And moreover, through an intermittent post-preheating and intake synchronous heating strategy, the combustion stability in the cylinder is effectively improved, the rotating speed fluctuation time is shortened, and mechanical damage caused by flameout and unstable idling after starting is avoided. In addition, the dragging rotating speed control based on the torque can prevent the problem of engine damage caused by accidental detonation after multiple starting failures.

Description

Technical Field

[0001] This invention relates to the field of heuristic heavy oil engine technology, and in particular to a control method for low-temperature cold start of a heuristic heavy oil engine. Background Technology

[0002] The integrated starter-driven heavy oil engine is a power unit formed by integrating a heavy oil engine and an integrated starter motor, mainly used for power generation and propulsion in special equipment. When performing cold start operations at low temperatures, this power unit requires the integrated starter motor to reverse-drive the heavy oil engine to complete the starting process. However, heavy oil itself has a high viscosity, and its atomization performance decreases significantly at low temperatures, resulting in poor uniformity of fuel-air mixing in the cylinder. This is especially true at ultra-low temperatures below -40°C, where the difficulty of cold starting increases dramatically. In oxygen-deficient environments such as high altitudes and high altitudes, this technical challenge is further exacerbated. Therefore, to ensure smooth starting of the heavy oil engine and maintain stable combustion in the cylinder after ignition, in addition to auxiliary preheating devices such as glow plugs and intake grilles, an efficient low-temperature cold start control strategy is also required.

[0003] Currently, the low-temperature cold start technology system for heavy oil engines is mainly built around three aspects: First, it relies on glow plugs, intake grilles, and oil auxiliary heating devices (such as heating pots, electric heaters, etc.) to ensure the success rate of cold starts; second, the glow plugs adopt preheating control logic before starting, and after each start-up process is completed, the engine controller ECU needs to be powered down to ensure that the preheating program can be effectively triggered for the next start; third, the starting towing method adopts a motor or starter motor reverse towing mode.

[0004] However, the aforementioned existing technical solutions have the following shortcomings in practical applications, specifically: Firstly, the heating pot system has a complex device structure and pipeline connection, and the heating time is nearly 20 minutes. Moreover, the heating pot is prone to unstable operation, which seriously restricts the efficiency of equipment mission execution. As for the electric heating system for fuel, engine oil and coolant, there are problems such as complex device and wiring layout, redundant insulation structure, and limited heating coverage, which cannot meet the preheating needs of the entire area. Secondly, relying solely on glow plugs for preheating can easily lead to unstable ignition or even stalling after the engine starts successfully; if the glow plug in one cylinder malfunctions, it will directly cause the engine to fail to start. Third, in the existing glow plug control strategy, after each engine drag is completed, the engine controller ECU needs to be powered down and restarted before the preheating program before the next drag can be triggered. However, the low-voltage power-down of the heavy oil power unit needs to be linked with the entire vehicle or aircraft system to complete. After the large system is powered on again, it takes time to complete the system self-check and reset process. Frequent power-up and power-down will greatly prolong the start-up preparation time, which contradicts the actual application requirement of supporting multiple start attempts with a single power-up. Fourth, after the preheating process is completed, the engine lacks continuous preheating during the engine dragging phase. If ignition fails to be achieved in a short time, the cylinder temperature will drop rapidly, causing the air-fuel mixture to fail to be effectively ignited, ultimately leading to start-up failure. Fifth, after the engine starts successfully, the ignition state in the cylinder is unstable, which can easily cause problems such as idling speed fluctuations and severe engine vibration. This not only aggravates internal engine wear but may also lead to sudden engine shutdown. Sixth, if a successful start occurs after multiple failed starts, abnormal combustion in the cylinder can easily lead to detonation, which in turn can cause serious mechanical failures such as crown melting and cylinder scoring, significantly shortening the engine's service life. Summary of the Invention

[0005] The purpose of this invention is to provide a control method for low-temperature cold start of a single-fuel heavy oil engine based on heuristics, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a control method for low-temperature cold start of a single-fuel heavy oil engine based on heuristics, the method comprising: S1. After receiving the low-voltage power-on command sent by the remote control unit (RCU), the ECU of the heavy oil engine automatically completes initialization and self-test, and feeds back fault information to the RCU in real time. S2. After receiving the start command from the remote control unit (RCU), the engine controller (ECU) determines whether a preheating operation needs to be performed based on preset parameters. If so, it controls the preheating execution module to start preheating; otherwise, it directly sends a preheating completion status bit to the remote control unit (RCU). S3. After receiving the preheating completion status, the remote control unit (RCU) controls the starter motor to reverse the engine with a preset torque. At the same time, the engine controller (ECU) delays for a preset time and then controls the preheating execution module to start dragging preheating, thereby realizing cold start control of dragging and preheating at the same time. S4. The engine controller ECU determines whether the start is successful based on the comparison between the engine speed and the target idle speed. If the start fails, the number of failures is recorded and the preheating and dragging preheating process is repeated after the restart conditions are met. If the start is successful, the preheating execution module is controlled to switch to the intermittent postheating mode. S5. In response to the engine idle speed fluctuation meeting the stable condition, the engine controller ECU controls the preheating execution module to stop preheating and complete the low temperature cold start process.

[0007] In some implementations, in step S2: The preset parameters include coolant temperature, lubricating oil temperature, intake manifold temperature, ambient temperature, and atmospheric pressure. The engine controller (ECU) determines whether preheating is required and the corresponding preheating time by using a parameter comparison algorithm and MAP table lookup.

[0008] In some implementations, in steps S2 and S3: The preheating execution module includes an in-cylinder glow plug and an intake air heating grille. The engine controller ECU synchronously controls the in-cylinder glow plug and the intake air heating grille through the same preheating relay. Both work synchronously during the preheating and drag preheating processes.

[0009] In some implementations, in step S3: During the process of the remote control unit (RCU) controlling the integrated starter motor to reverse the engine with a preset torque, the dragging torque is obtained by querying the calibrable CUR table, and the maximum dragging speed of the engine is not higher than 400 r / min. The dragging time is determined by querying the calibrable CUR table and the initial dragging time does not exceed 30 seconds. The engine controller ECU delays for a preset time before controlling the preheating execution module to start the drag preheating process. The delay time is 1 second. The drag preheating and the motor reverse dragging process are carried out synchronously until the start attempt ends.

[0010] In some implementations, in step S4: The engine controller ECU determines whether the start is successful based on whether the engine speed is greater than the target idle speed, and the target idle speed is obtained by querying the calibrable CUR table; During the process of dragging and preheating, the system employs a fuel injection mode with preset rail pressure, two pre-injections, and one main injection, along with the appropriate injection timing determined by querying the MAP table.

[0011] In some implementations, step S4, which involves recording the number of failures if startup fails and repeating the preheating and drag-while-warming process after the restart conditions are met, includes: The engine controller ECU records the number of start failures. After the engine speed is below 20 r / min and is determined to be in a stopped state, it re-determines whether preheating is required based on preset parameters. After preheating is completed, the next start-up while dragging and preheating is executed. The maximum number of startup attempts per power-on cycle is 3.

[0012] In some implementations, if all three start attempts fail, the engine controller ECU uploads the start failure status bit and fault code to the remote control unit RCU via a message and requests a power-down troubleshooting. After the power-down fault troubleshooting is completed, a new round of cold start process can be started by powering on again. In the state of not powering off, new preheating and drag start actions cannot be triggered.

[0013] In some implementations, during step S4, the process of switching the preheating execution module to the intermittent post-preheating mode if the startup is successful: The post-preheating interval and the upper limit of the post-preheating time can be obtained by querying the calibrable MAP table.

[0014] In some implementations, step S4, if the startup is successful, further includes: The engine controller (ECU) immediately sends a start-up success status bit to the remote control unit (RCU). Upon receiving the bit, the RCU controls the integrated starter motor to switch from drag mode to follow-rotation mode. If the engine fails to maintain the target idle speed and eventually shuts down after a successful start, the engine controller ECU determines that the start has failed and records the number of failures.

[0015] In some implementations, in step S5, when the engine idle speed fluctuation meets the stability condition, the engine controller ECU controls the preheating execution module to stop preheating to complete the low-temperature cold start process, including: When the engine idle speed fluctuation is less than 20 r / min, the engine controller ECU sends a low-level signal to control the preheating relay to disconnect, and then the preheating ends.

[0016] The beneficial effects of the technical solution provided by this invention include at least the following: This technical solution combines in-cylinder glow plugs with intake air heating grilles, synchronously controlled by a single relay. Sufficient battery capacity meets the power requirements for simultaneous operation and preheating while being driven, making it suitable for ultra-low temperatures below -40℃ and high-altitude environments above 4700m. This significantly improves cold start success rate and idle stability after startup. Intelligent preheating control logic enables three start attempts per power-on, each executing preheating and simultaneous heating while being driven. Failed starts are automatically reported with fault information, eliminating the need for frequent power-offs and improving starting efficiency. Furthermore, intermittent post-preheating and synchronous intake air heating strategies effectively improve in-cylinder combustion stability, shorten speed fluctuation time, and prevent mechanical damage caused by stalling and unstable idling after startup. Additionally, torque-based drive speed control prevents engine damage caused by occasional detonation after multiple failed starts. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0018] Figure 1 The diagram shows a schematic flow chart of a control method for low-temperature cold start of a heavy oil engine based on an exemplary embodiment of the present invention.

[0019] Figure 2 The diagram illustrates a logic block diagram of a control method for low-temperature cold start of a heavy oil engine based on an exemplary embodiment of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] Figure 1 The diagram illustrates a flow chart of a control method for low-temperature cold start of a heavy-duty oil engine based on an exemplary embodiment of the present invention. Figure 2 The diagram illustrates a logic block diagram of a control method for low-temperature cold start of a heuristic-based heavy-duty oil engine, provided by an exemplary embodiment of the present invention. The control method includes: Step S1: After the ECU of a heavy oil engine receives the low-voltage power-on command sent by the remote control unit (RCU), it automatically completes initialization and self-test, and feeds back fault information to the RCU in real time.

[0023] In this embodiment, the engine controller (ECU) is the execution unit that initiates the cold start and operation control of a heavy oil engine. As the local control center, its functions include receiving various sensor parameters, parsing remote control unit (RCU) commands, implementing key operations such as preheating control, fuel injection adjustment, and start-up status judgment through built-in logic algorithms, and providing real-time feedback on system status and fault information. The remote control unit (RCU) serves as a bridge connecting external control requirements and local execution, undertaking the responsibilities of initiating remote commands (such as low-voltage power-on and start commands), receiving feedback data from the engine controller (ECU), and controlling the switching of the starter motor's operating mode according to status commands. The two establish bidirectional communication through messages.

[0024] In this embodiment, the ECU's initialization upon receiving the RCU power-on command quickly resets each control module to a ready state, eliminating residual parameter interference from the previous work cycle and ensuring that subsequent cold start control logic operates based on standard benchmarks. The self-test function focuses on the effectiveness of hardware (such as sensors and actuators) and software programs, proactively identifying circuit faults and module anomalies to avoid engine or electronic control unit damage caused by starting with faults. Real-time feedback of fault information to the RCU allows the RCU to accurately grasp the pre-start status; if a fault exists, the starting process can be terminated promptly to avoid invalid attempts; if the status is normal, subsequent commands are triggered, forming a closed-loop management system.

[0025] Step S2: After receiving the start command from the remote control unit (RCU), the engine controller (ECU) determines whether a preheating operation needs to be performed based on preset parameters. If so, it controls the preheating execution module to start the preheating. If not, it directly sends a preheating completion status bit to the RCU.

[0026] In some embodiments, the preset parameters include coolant temperature, lubricating oil temperature, intake manifold temperature, ambient temperature and atmospheric pressure, and the engine controller ECU determines whether preheating is required and the corresponding preheating time by using a parameter comparison algorithm and MAP table lookup.

[0027] In this embodiment, the MAP table is a two-dimensional or multi-dimensional data mapping table in the field of engine control that stores the correlation between engine operating parameters (such as temperature and pressure) and corresponding control parameters (such as injection timing and preheating time), and the parameters can be calibrated as needed. After receiving the RCU start command, the ECU does not directly execute the action, but instead constructs an operating condition judgment model through multi-dimensional preset parameters. The coolant and lubricating oil temperatures reflect the basic state of the engine, the intake manifold temperature is related to the combustion environment, and the ambient temperature and atmospheric pressure are adapted to complex scenarios such as high altitude and low temperature, ensuring that the judgment does not deviate from the actual operating conditions. The combination of parameter comparison algorithm and MAP table frees the decision of whether to preheat and for how long from experience dependence, avoids starting difficulties caused by lack of preheating at low temperatures, and prevents energy waste and component wear caused by ineffective preheating at normal temperature. The setting of the status bit feedback to the RCU provides a clear signal for the RCU to trigger subsequent drag actions.

[0028] In one example, the implementation logic of the parameter comparison algorithm is as follows: The collected preset parameters, such as coolant temperature, lubricating oil temperature, intake manifold temperature, ambient temperature, and atmospheric pressure, are standardized to eliminate errors caused by differences in the range of different sensors. Each parameter is uniformly converted to the dimensionless range [0,1] for easier subsequent multi-parameter collaborative analysis. Each standardized parameter is then compared one by one with its corresponding cold start preheating threshold. These thresholds are calibrated through numerous low-temperature experiments based on the engine model and heavy oil grade. The algorithm determines whether a single parameter meets the temperature / pressure condition of "no preheating required." If any parameter is below the corresponding threshold, a preheating requirement is initially identified. Combining atmospheric pressure, a correction parameter that significantly affects combustion efficiency, a weighted algorithm is used to comprehensively evaluate the overall preheating requirement. The weights of each parameter are set according to their impact on the cold start success rate (e.g., coolant temperature weight 0.35, lubricating oil temperature weight 0.3, intake manifold temperature weight 0.2, ambient temperature weight 0.1, atmospheric pressure weight 0.05). After calculating the comprehensive requirement coefficient, the algorithm matches the preset MAP table to output the judgment result of whether preheating is required and the corresponding precise preheating time.

[0029] Step S3: After receiving the preheating completion status, the remote control unit (RCU) controls the starter motor to reverse the engine with a preset torque. At the same time, the engine controller (ECU) delays for a preset time and then controls the preheating execution module to start dragging and preheating, thus achieving cold start control with dragging and preheating simultaneously.

[0030] In some embodiments, the preheating execution module includes an in-cylinder glow plug and an intake air heating grille. The engine controller ECU synchronously controls the in-cylinder glow plug and the intake air heating grille through the same preheating relay. Both work synchronously during the preheating and drag preheating processes.

[0031] In this embodiment, the RCU controls the motor to reverse after receiving the preheating completion signal, providing basic operating power to the engine. The ECU delays the triggering of the preheating to avoid electrical conflicts at the moment of motor start-up, ensuring that the cylinder temperature is maintained continuously during the reversing process, thus solving the problem of cylinder temperature loss in traditional preheating followed by reversing. The synchronous control design of the in-cylinder preheating plug and the intake air heating grille achieves dual-dimensional heating of the cylinder and intake air through the same relay, simplifying the hardware chain and allowing the atomized heavy fuel oil to mix fully with the heated air, improving the probability of in-cylinder ignition. This simultaneous reversing and heating mode can compensate for the defects of poor fluidity and harsh combustion conditions of heavy fuel oil in ultra-low temperature environments of -40℃ or high-altitude environments, while achieving efficient energy utilization.

[0032] In some embodiments, during the process of the remote control unit (RCU) controlling the starter motor to reverse the engine with a preset torque, the drag torque is obtained by querying a calibrable CUR table, and the maximum drag speed of the engine is not higher than 400 r / min. The drag time is determined by querying a calibrable CUR table, and the initial drag time does not exceed 30s. After a preset delay, the engine controller (ECU) controls the preheating execution module to start the drag preheating process. The delay time is 1s. The drag preheating is carried out synchronously with the motor reverse dragging process until the start attempt ends.

[0033] In this embodiment, the torque and time configuration is centered on a calibrated CUR table (i.e., a mapping table that stores the correspondence between operating conditions and drag parameters, and whose parameter values ​​can be adjusted according to actual needs). This allows the drag parameters to adapt to different environments and engine states. Through dynamic query and adjustment, it avoids the problem of insufficient power or excessive energy consumption under conditions such as low temperature and high altitude when fixed parameters are used. The maximum drag speed is limited to 400 r / min to prevent mechanical failures such as engine crown melting and cylinder scoring caused by the accumulated fuel from the previous unsuccessful in-cylinder start-up when the drag speed is too high. The 30-second initial drag time limit forms a loss-prevention mechanism to avoid motor overload caused by ineffective drag. The 1-second preheating delay design cleverly avoids the high current peak at the moment of motor start-up, preventing circuit load superposition and failure, while ensuring seamless connection between preheating and dragging, maintaining stable in-cylinder temperature, and providing continuously favorable conditions for ignition and combustion.

[0034] Step S4: The engine controller ECU determines whether the start is successful based on the comparison between the engine speed and the target idle speed. If the start fails, the number of failures is recorded and the preheating and dragging preheating process is repeated after the restart conditions are met. If the start is successful, the preheating execution module is controlled to switch to the intermittent postheating mode.

[0035] In some embodiments, the engine controller ECU determines whether the start-up is successful based on whether the engine speed is greater than the target idle speed, which is obtained by querying a calibrable CUR table; wherein, during the process of dragging and preheating, a fuel injection mode of preset rail pressure, 2 pre-injections + 1 main injection is adopted, and the appropriate fuel injection time is queried through the MAP table.

[0036] In this embodiment, the ECU uses speed comparison as the judgment basis. The target idle speed is obtained through a calibrable CUR table to ensure that the judgment standard can match different environments and engine models, avoiding misjudgments caused by fixed thresholds. The fault-tolerant design after a failed start improves the success rate under complex operating conditions by recording the number of times and repeating the start-up process, while ensuring equipment safety, and solves the limitation of traditional start-up termination after a single failure. After a successful start, switching to intermittent post-warm-up is the transition from start-up combustion to stable operation. The accompanying 2-pre-injection + 1-main-injection strategy can build a suitable combustion environment in advance. Combined with the injection timing, it forms a closed loop with the speed judgment logic, improving start-up reliability.

[0037] In some embodiments, if a start fails, the number of failures is recorded, and the preheating and drag-and-start process is repeated after the restart conditions are met. This includes: the engine controller ECU records the number of start failures, waits for the engine speed to drop below 20 r / min to be considered a shutdown state, then re-determines whether preheating is needed based on preset parameters, and executes the next drag-and-start start after preheating is completed; the maximum number of start attempts in a single power-on cycle is 3. If all 3 start attempts fail, the engine controller ECU uploads the start failure status bit and fault code to the remote control unit (RCU) via a message and requests a power-down troubleshooting; after the power-down fault troubleshooting is completed, a new round of cold start process can be started by powering on again; no new preheating and drag-and-start actions can be triggered while the power is off.

[0038] In some embodiments, if the startup is successful, during the process of controlling the preheating execution module to switch to the intermittent post-preheating mode: the post-preheating interval time and the upper limit of the post-preheating time are obtained by querying the calibrable MAP table.

[0039] In this embodiment, intermittent post-heating abandons continuous heating and maintains a suitable cylinder temperature through intermittent heat replenishment, thus solving the problem of unstable combustion during the initial start-up phase. A calibrated MAP table provides flexible adaptability for post-heating parameters, and can output the optimal interval and time limit based on real-time operating conditions such as ambient temperature and altitude, ensuring precise control in scenarios such as high altitude and ultra-low temperatures.

[0040] In some embodiments, if the start is successful, the engine controller ECU immediately sends a start success status bit to the remote control unit RCU. After receiving the bit, the remote control unit RCU controls the starter motor to switch from the drag mode to the follow rotation mode. If the engine cannot maintain the target idle speed and eventually shuts down after the start is successful, the engine controller ECU determines that the start has failed and records the number of failures.

[0041] In this embodiment, the ECU immediately sends a success status bit, providing a trigger signal for the RCU to switch the motor mode. The motor switches from dragging to following rotation, stopping invalid power output and saving energy. The failure judgment mechanism for engine shutdown after startup completes the verification logic for successful startup, preventing the situation where a brief startup followed by engine shutdown is mistakenly judged as successful. By recording the number of failures, it connects to subsequent restart or troubleshooting processes, making cold start control more in line with actual operating conditions.

[0042] Step S5: In response to the engine idle speed fluctuation meeting the stability condition, the engine controller ECU controls the preheating execution module to stop preheating, thus completing the low-temperature cold start process.

[0043] In some embodiments, in response to the engine idle speed fluctuation meeting a stable condition, the engine controller ECU controls the preheating execution module to stop preheating, completing the low-temperature cold start process. This includes: in response to the engine idle speed fluctuation being less than 20 r / min, the engine controller ECU sends a low-level signal to control the preheating relay to disconnect, and then the preheating ends. At this point, the low-temperature cold start of a heavy oil engine is complete, and the warm-up phase begins.

[0044] In summary, this technical solution combines in-cylinder glow plugs with intake air heating grilles, synchronously controlled by the same relay. It relies on sufficient battery capacity to meet the power requirements for simultaneous operation and preheating while being driven, making it suitable for ultra-low temperatures below -40℃ and high-altitude environments above 4700m. This significantly improves cold start success rate and idle stability after startup. Intelligent preheating control logic enables three start attempts per power-on, each executing preheating and simultaneous heating while being driven. Failed starts are automatically reported with fault information, eliminating the need for frequent power-offs and improving starting efficiency. Furthermore, intermittent post-preheating and synchronous intake air heating strategies effectively improve in-cylinder combustion stability, shorten speed fluctuation time, and prevent mechanical damage caused by stalling after startup and unstable idling. Additionally, torque-based drive speed control can prevent engine damage caused by occasional detonation after multiple failed starts.

[0045] It is understood that the specific examples in this document are only intended to help those skilled in the art better understand this disclosure, and are not intended to limit the scope of the invention.

[0046] It is understood that in the various embodiments of this specification, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of this disclosure.

[0047] It is understood that the various implementation methods described in this specification can be implemented individually or in combination, and this disclosure does not limit them.

[0048] Unless otherwise stated, all technical and scientific terms used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of this specification. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items. The singular forms "a," "the," and "the" as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0049] Those skilled in the art will recognize that the algorithmic steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this specification.

[0050] The above description is merely a specific embodiment of this specification, but the scope of protection of this invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this specification should be included within the scope of protection of this specification. Therefore, the scope of protection of this invention should be determined by the scope of the claims.

Claims

1. A control method for low-temperature cold start of a single-fuel heavy oil engine based on heuristics, characterized in that, The method includes: S1. After receiving the low-voltage power-on command sent by the remote control unit (RCU), the ECU of the heavy oil engine automatically completes initialization and self-test, and feeds back fault information to the RCU in real time. S2. After receiving the start command from the remote control unit (RCU), the engine controller (ECU) determines whether a preheating operation needs to be performed based on preset parameters. If so, it controls the preheating execution module to start preheating; otherwise, it directly sends a preheating completion status bit to the remote control unit (RCU). S3. After receiving the preheating completion status, the remote control unit (RCU) controls the starter motor to reverse the engine with a preset torque. At the same time, the engine controller (ECU) delays for a preset time and then controls the preheating execution module to start dragging preheating, thereby realizing cold start control of dragging and preheating at the same time. S4. The engine controller ECU determines whether the start is successful based on the comparison between the engine speed and the target idle speed. If the start fails, the number of failures is recorded and the preheating and dragging preheating process is repeated after the restart conditions are met. If the start is successful, the preheating execution module is controlled to switch to the intermittent postheating mode. S5. In response to the engine idle speed fluctuation meeting the stable condition, the engine controller ECU controls the preheating execution module to stop preheating and complete the low temperature cold start process.

2. The control method for low-temperature cold start of a heuristic-based heavy-duty oil engine according to claim 1, characterized in that, In step S2: The preset parameters include coolant temperature, lubricating oil temperature, intake manifold temperature, ambient temperature, and atmospheric pressure. The engine controller (ECU) determines whether preheating is required and the corresponding preheating time by using a parameter comparison algorithm and MAP table lookup.

3. The control method for low-temperature cold start of a heuristic-based heavy-duty oil engine according to claim 1, characterized in that, In steps S2 and S3: The preheating execution module includes an in-cylinder glow plug and an intake air heating grille. The engine controller ECU synchronously controls the in-cylinder glow plug and the intake air heating grille through the same preheating relay. Both work synchronously during the preheating and drag preheating processes.

4. The control method for low-temperature cold start of a heuristic-based heavy-duty oil engine according to claim 1, characterized in that, In step S3: During the process of the remote control unit (RCU) controlling the integrated starter motor to reverse the engine with a preset torque, the dragging torque is obtained by querying the calibrable CUR table, and the maximum dragging speed of the engine is not higher than 400 r / min. The dragging time is determined by querying the calibrable CUR table and the initial dragging time does not exceed 30 seconds. The engine controller ECU delays for a preset time before controlling the preheating execution module to start the drag preheating process. The delay time is 1 second. The drag preheating and the motor reverse dragging process are carried out synchronously until the start attempt ends.

5. The control method for low-temperature cold start of a heuristic-based heavy-duty oil engine according to claim 1, characterized in that, In step S4: The engine controller ECU determines whether the start is successful based on whether the engine speed is greater than the target idle speed, and the target idle speed is obtained by querying the calibrable CUR table; During the process of dragging and preheating, the system employs a fuel injection mode with preset rail pressure, two pre-injections, and one main injection, along with the appropriate injection timing determined by querying the MAP table.

6. The control method for low-temperature cold start of a heuristic-based heavy-duty oil engine according to claim 1, characterized in that, In step S4, the step of recording the number of failures if startup fails and repeating the preheating and drag-and-go preheating process after the restart conditions are met includes: The engine controller ECU records the number of start failures. After the engine speed is below 20 r / min and is determined to be in a stopped state, it re-determines whether preheating is required based on preset parameters. After preheating is completed, the next start-up while dragging and preheating is executed. The maximum number of startup attempts per power-on cycle is 3.

7. The control method for low-temperature cold start of a heuristic-based heavy-duty oil engine according to claim 6, characterized in that, If all three start attempts fail, the engine controller (ECU) uploads the start failure status bit and fault code to the remote control unit (RCU) via a message and requests a power-down troubleshooting. After the power-down troubleshooting is completed, a new round of cold start process can be started by powering on again. In the state of not powering off, new preheating and drag start actions cannot be triggered.

8. The control method for low-temperature cold start of a heuristic-based heavy-duty oil engine according to claim 1, characterized in that, In step S4, during the process of switching the preheating execution module to the intermittent post-preheating mode if the startup is successful: The post-preheating interval and the upper limit of the post-preheating time can be obtained by querying the calibrable MAP table.

9. The control method for low-temperature cold start of a heuristic-based heavy oil engine according to claim 1, characterized in that, If the startup is successful, step S4 also includes: The engine controller (ECU) immediately sends a start-up success status bit to the remote control unit (RCU). Upon receiving the bit, the RCU controls the integrated starter motor to switch from drag mode to follow-rotation mode. If the engine fails to maintain the target idle speed and eventually shuts down after a successful start, the engine controller ECU determines that the start has failed and records the number of failures.

10. The control method for low-temperature cold start of a heuristic-based heavy oil engine according to claim 1, characterized in that, In step S5, when the engine idle speed fluctuation meets the stability condition, the engine controller ECU controls the preheating execution module to stop preheating, completing the low-temperature cold start process, including: When the engine idle speed fluctuation is less than 20 r / min, the engine controller ECU sends a low-level signal to control the preheating relay to disconnect, and then the preheating ends.

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