Method for preventing over-speed and black smoke in all working conditions of a four-stroke marine engine

Abstract

A method for preventing overspeeding and black smoke emission from a four-stroke marine engine under all operating conditions is disclosed, relating to the field of four-stroke marine engine control technology. This method addresses the problem of existing technologies failing to achieve full-condition fuel quantity limitation and exhibiting low control precision, leading to black smoke emission from the engine. The method involves collecting a 4-20mA current signal corresponding to the boost air pressure as the main engine load feedback signal; connecting this signal to the electronic speed controller via a shielded anti-interference link; setting fuel quantity limitation parameters according to eight speed ranges and at least eight load points in each range within a speed range of 200-1080 r / min and a boost air pressure range of 10-200 kPa, and periodically calibrating these parameters; dynamically adjusting the fuel supply using a PID control algorithm to predictively prevent speed deviations; and incorporating an abnormal alarm and a local + cloud encrypted storage module. The beneficial effects are: ensuring the engine speed remains stable within a safe range and avoiding black smoke emission caused by excessive fuel quantity under different operating conditions.

Description

Technical Field

[0001] This invention relates to the field of four-stroke marine engine control technology, specifically to a method for preventing overspeeding and black smoke emission from a four-stroke marine engine under all operating conditions. Background Technology

[0002] With the widespread adoption of electronic governors (EGGs) in marine main engines, their applications are expanding. However, their inherent speed control characteristics dictate that they can only adjust fuel quantity based on engine speed. Under various special operating conditions during ship navigation, EGGs often increase the throttle to maintain engine speed, leading to excessive fuel supply to the main engine and subsequently causing problems such as black smoke from the main engine.

[0003] Based on feedback from the shipbuilding market, black smoke emissions during main engine startup and operation are common and severe. This is especially true given the increasingly stringent environmental policies, which place higher demands on engine emissions and operational stability, requiring higher standards for the speed control characteristics of main engine governors. Current technologies often employ external solenoid valves to control mechanical pushrod structures, limiting fuel flow at a fixed position. This fails to manage fuel flow across speed ranges outside this fixed position, making it difficult to achieve electronic fuel and speed limiting under all operating conditions. Consequently, it cannot fundamentally solve the technical problems of engine overspeeding and black smoke emissions.

[0004] Therefore, this invention proposes a method for preventing overspeeding and black smoke emission from a four-stroke marine engine under all operating conditions, in order to solve the aforementioned problems. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preventing overspeed and black smoke emission from a four-stroke marine engine under all operating conditions, in order to solve the problem that existing technologies cannot achieve full-condition fuel quantity limitation and have low control precision, resulting in the engine emitting black smoke.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] A method for preventing overspeeding and black smoke emission from a four-stroke marine engine under all operating conditions, characterized by comprising the following steps:

[0008] S1. Acquire the main engine load feedback signal of the four-stroke marine engine. The main engine load feedback signal is a 4-20mA current signal corresponding to the boost air pressure, and the boost air pressure changes synchronously with the change of the main engine load. Acquire the boost air pressure signal using a boost air pressure sensor. The boost air pressure sensor has a measurement accuracy of ±1kPa and a measurement range of 0-250kPa. The boost air pressure sensor is installed at the outlet of the engine's boost air pipeline.

[0009] S2. Connect the host load feedback signal to the electronic speed controller to establish a signal transmission link between the host load feedback signal and the electronic speed controller; the signal transmission link uses a shielded cable, the shielding layer of the shielded cable is grounded, and an anti-interference module is connected on the signal transmission path.

[0010] S3. Start the electronic speed controller and enter the fuel quantity control mAp interface. The main engine speed range is 200-1080 r / min, and the boost air pressure range is 10-200 kPa. Set the fuel quantity limit parameters for different operating conditions for different speed ranges and different boost air pressures. The main engine speed range is divided into 8 intervals: 200-500 r / min, 500-600 r / min, 600-700 r / min, 700-800 r / min, 800-900 r / min, 900-1000 r / min, 1000-1030 r / min, and 1030-1080 r / min. Set at least 8 fuel quantity limit parameters corresponding to boost air pressures in each speed interval.

[0011] S4. Based on the fuel quantity limit parameters and the electronic speed controller, the fuel supply to the main unit is dynamically adjusted. The electronic speed controller uses a PID control algorithm to adjust the fuel supply, with a response time of no more than 100ms. The electronic speed controller compares the real-time speed of the main unit with the preset safe speed range in real time. When the real-time speed is 1080r / min±5r / min, the fuel supply is reduced in advance.

[0012] S5. Set up an abnormal operating condition alarm module, which is connected to the audible and visual alarm and the electronic speed controller; the audible and visual alarm includes sound alarm and light alarm, the sound alarm is not less than 80dB, the light alarm uses red LED lights, and the audible and visual alarm will feed back abnormal data to the ship monitoring system.

[0013] S6. Establish a data storage module. This module receives host load feedback signals, booster air pressure signals, and fuel supply data. It is also connected to an abnormal operating condition alarm module. The data storage module includes local storage and cloud backup. Local storage uses solid-state drives, while cloud backup uses encrypted transmission.

[0014] Furthermore, it also includes a filtering process for the host load feedback signal. After the boosted air pressure signal is acquired in step S1, the signal is filtered by a low-pass filter with a cutoff frequency of 10Hz.

[0015] Furthermore, it also includes a calibration step for the fuel quantity limit parameter, which is calibrated based on historical operating data, standard operating condition data, and manually input calibration parameters.

[0016] In summary, the beneficial effects of this invention compared to the prior art are as follows:

[0017] 1. This invention uses a 4-20mA current signal corresponding to the boosted air pressure as the host load feedback signal. Combined with filtering and a high-precision pressure sensor, it ensures the accuracy and stability of the load signal. At the same time, the speed range is subdivided into 8 intervals, and each interval is set with at least 8 oil quantity limit parameters corresponding to the load. This achieves full-condition oil quantity coverage for the 200-1080r / min speed range and the 10-200kPa boosted air pressure range, avoiding the black smoke phenomenon caused by excessive oil quantity under different operating conditions.

[0018] 2. This invention optimizes the signal transmission link by using shielded cables, grounding treatment, and anti-interference modules to reduce signal interference. It adopts a PID control algorithm to achieve dynamic and precise adjustment of fuel supply, and combined with predictive fuel control, it significantly improves the fuel supply control accuracy. This effectively solves the problem of low control accuracy and slow response caused by speed deviation in existing technologies, ensuring that the engine speed remains stable within a safe range. Attached Figure Description

[0019] Figure 1 This is a flowchart of the method of the present invention;

[0020] Figure 2 This is a two-dimensional table showing the effect of the main engine speed and booster air pressure on the oil quantity limiting parameters of this invention;

[0021] Figure 3 A three-dimensional map of the effect of main engine speed and booster air pressure on oil quantity limiting parameters in this invention;

[0022] Figure 4 This invention provides a visual mechanical view of the relationship between the host machine's rotational speed and boosted air pressure. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0024] In this application, the terms "upper," "inner," "outer," "middle," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0025] A method for preventing overspeeding and black smoke emission from a four-stroke marine engine under all operating conditions, characterized by comprising the following steps:

[0026] S1. Acquire the main engine load feedback signal of the four-stroke marine engine. The main engine load feedback signal adopts a 4-20mA current signal corresponding to the boost air pressure. The boost air pressure changes synchronously with the change of the main engine load. A boost air pressure sensor is used to acquire the boost air pressure signal. The measurement accuracy of the boost air pressure sensor is ±1kPa, and the measurement range is 0-250kPa. The boost air pressure sensor is installed at the outlet position of the engine's boost air pipeline.

[0027] S2. Connect the host load feedback signal to the electronic speed controller to establish a signal transmission link between the host load feedback signal and the electronic speed controller; the signal transmission link uses a shielded cable, the shielding layer of the shielded cable is grounded, and an anti-interference module is connected on the signal transmission path.

[0028] S3. Start the electronic speed controller and enter the fuel quantity control mAp interface. The main engine speed range is 200-1080 r / min, and the boost air pressure range is 10-200 kPa. Set the fuel quantity limit parameters for different operating conditions for different speed ranges and different boost air pressures. The main engine speed range is divided into 8 intervals: 200-500 r / min, 500-600 r / min, 600-700 r / min, 700-800 r / min, 800-900 r / min, 900-1000 r / min, 1000-1030 r / min, and 1030-1080 r / min. Set at least 8 fuel quantity limit parameters corresponding to boost air pressures in each speed interval.

[0029] S4. Based on the fuel quantity limit parameters and the electronic speed controller, the fuel supply to the main unit is dynamically adjusted. The electronic speed controller uses a PID control algorithm to adjust the fuel supply, with a response time of no more than 100ms. The electronic speed controller compares the real-time speed of the main unit with the preset safe speed range in real time. When the real-time speed is 1080r / min±5r / min, the fuel supply is reduced in advance.

[0030] S5. Set up an abnormal operating condition alarm module, which is connected to the audible and visual alarm and the electronic speed controller; the audible and visual alarm includes sound alarm and light alarm, the sound alarm is not less than 80dB, the light alarm uses red LED lights, and the audible and visual alarm will feed back abnormal data to the ship monitoring system.

[0031] S6. Establish a data storage module. This module receives host load feedback signals, booster air pressure signals, and fuel supply data. It is also connected to an abnormal operating condition alarm module. The data storage module includes local storage and cloud backup. Local storage uses solid-state drives, while cloud backup uses encrypted transmission.

[0032] Furthermore, it also includes a filtering process for the host load feedback signal. After the boosted air pressure signal is acquired in step S1, the signal is filtered by a low-pass filter with a cutoff frequency of 10Hz.

[0033] Furthermore, it also includes a calibration step for the fuel quantity limit parameter, which is calibrated based on historical operating data, standard operating condition data, and manually input calibration parameters.

[0034] Example 1: A method for preventing overspeeding and black smoke emission in a four-stroke marine engine under all operating conditions. This example is applied to a medium-sized four-stroke marine diesel engine with a rated speed of 1080 r / min, an idle speed of 200 r / min, and a boost air pressure range of 10-200 kPa. The method of this invention solves the problems of black smoke emission and excessive speed deviation caused by the lack of oil control and low accuracy under all operating conditions in the prior art. The specific steps are as follows:

[0035] 1. Signal Acquisition and Filtering: A boost air pressure sensor (measurement accuracy ±1kPa, measurement range 0-250kPa) is installed at the outlet of the engine boost air duct to acquire the boost air pressure signal, which changes synchronously with the host load. The acquired pressure signal is filtered by a low-pass filter (cutoff frequency 10Hz) to filter out high-frequency interference noise, and the processed pressure signal is converted into a 4-20mA current signal (host load feedback signal).

[0036] 2. Signal transmission link setup: Shielded cables are used to connect the host load feedback signal to the electronic speed controller. The shielding layer of the shielded cable is grounded. At the same time, an anti-interference module is connected in series on the signal transmission path to suppress external electromagnetic interference, ensure accurate and stable signal transmission, and avoid oil control errors caused by signal distortion.

[0037] 3. Fuel Quantity Limit Parameter Setting and Calibration: Start the electronic speed controller and enter the fuel quantity control Map interface. Divide the main engine speed range into 8 intervals (200-500r / min, 500-600r / min, 600-700r / min, 700-800r / min, 800-900r / min, 900-1000r / min, 1000-1030r / min, 1030-1080r / min). Set 8 boost air pressures (10kPa, 30kPa, 50kPa, 80kPa, 120kPa, 150kPa, 180kPa, 200kPa) corresponding to the fuel quantity limit parameters within each speed interval. The parameter settings are based on the standard operating condition data from engine bench tests. The fuel quantity limit parameters are calibrated monthly based on historical operating data, standard operating condition data, and manually entered calibration parameters to ensure parameter accuracy.

[0038] 4. Dynamic adjustment of fuel supply: The electronic speed controller adopts a PID control algorithm. Based on the real-time collected main engine speed and booster air pressure signals, it matches the corresponding fuel supply limit parameters to dynamically adjust the fuel supply of the main engine. The adjustment response time is controlled within 85ms. At the same time, it compares the real-time speed of the main engine with the preset safe speed range. When the real-time speed reaches 1075r / min or 1085r / min (1080r / min±5r / min), it reduces the fuel supply in advance to prevent the speed from exceeding the tolerance.

[0039] 5. Abnormal Alarms and Data Storage: An abnormal operating condition alarm module is set up, connected to an audible and visual alarm (85dB sound alarm and red LED light alarm) and an electronic speed controller. When abnormal operating conditions such as excessive speed deviation or fuel supply exceeding the limit are detected, the audible and visual alarms are immediately triggered, and the abnormal data is fed back to the ship's monitoring system. A data storage module is established, using solid-state drives for local storage, while cloud backup is achieved through encrypted transmission. The module stores main engine load feedback signals, booster air pressure signals, fuel supply data, and abnormal operating condition data, retaining the data for subsequent troubleshooting and optimization.

[0040] After the application of this embodiment, the four-stroke marine engine achieves precise fuel quantity control across the entire speed range of 200-1080 r / min and the full load range of 10-200 kPa, with no black smoke emission; the speed deviation is controlled within ±3 r / min, completely solving the core problem of the existing technology; abnormal operating conditions can be alarmed in time, and the data can be traced, significantly improving the engine's operational stability and environmental friendliness.

[0041] Example 2: A method for preventing overspeeding and black smoke emission from a four-stroke marine engine under all operating conditions. This example applies to a small four-stroke marine gasoline engine with a rated speed of 1080 r / min, an idle speed of 200 r / min, and a boost air pressure range of 10-200 kPa. The specific steps are basically the same as in Example 1, with the following differences:

[0042] 1. Ten fuel quantity limit parameters corresponding to boost air pressure are set within each speed range to further improve the precision of fuel quantity control under all operating conditions;

[0043] 2. The PID control response time has been optimized to 70ms, improving the real-time performance of fuel quantity adjustment and further reducing the probability of speed deviation.

[0044] 3. The calibration cycle for fuel quantity limit parameters has been shortened to once every 15 days, to better suit the more frequent load changes in small engines;

[0045] 4. The sound and light alarm has been upgraded to 90dB, which is suitable for the noisy environment of the small boat's wheelhouse and ensures that the operator can detect abnormalities in time.

[0046] After the application of this embodiment, the small four-stroke marine gasoline engine operates without emitting black smoke under all working conditions, and the speed deviation is ≤±2r / min. It effectively solves the core problem of the existing technology and is suitable for the operating characteristics of small ships, making it highly practical.

Claims

1. A method for preventing overspeeding and black smoke emission from a four-stroke marine engine under all operating conditions, characterized in that, Includes the following steps: S1. Acquire the main engine load feedback signal of the four-stroke marine engine. The main engine load feedback signal adopts a 4-20mA current signal corresponding to the boosted air pressure. The boosted air pressure changes synchronously with the change of the main engine load. S2. Connect the host load feedback signal to the electronic speed controller to establish a signal transmission link between the host load feedback signal and the electronic speed controller; S3. Start the electronic speed controller and enter the fuel quantity control interface. The main engine speed range is 200-1080 r / min, and the booster air pressure range is 10-200 kPa. Set the fuel quantity limit parameters for different operating conditions corresponding to different speed ranges and different booster air pressures. S4. The fuel supply to the main unit is dynamically adjusted according to the fuel quantity limit parameters and the electronic speed controller; S5. Set up an abnormal operating condition alarm module, which is connected to an audible and visual alarm and an electronic speed controller; S6. Establish a data storage module. The data storage module is connected to the host load feedback signal, booster air pressure signal and fuel supply data. The data storage module is also connected to the abnormal operating condition alarm module.

2. The method for preventing overspeeding and black smoke emission from a four-stroke marine engine under all operating conditions according to claim 1, characterized in that, In step S1, a boost air pressure sensor is used to collect the boost air pressure signal. The boost air pressure sensor has a measurement accuracy of ±1 kPa and a measurement range of 0-250 kPa. The boost air pressure sensor is installed at the outlet of the engine boost air pipeline.

3. The method for preventing overspeeding and black smoke emission from a four-stroke marine engine under all operating conditions according to claim 1, characterized in that, In step S2, a shielded cable is used for the signal transmission link, the shielding layer of the shielded cable is grounded, and an anti-interference module is connected to the signal transmission path.

4. The method for preventing overspeeding and black smoke emission from a four-stroke marine engine under all operating conditions according to claim 1, characterized in that, In step S3, the main engine speed range is divided into 8 intervals: 200-500 r / min, 500-600 r / min, 600-700 r / min, 700-800 r / min, 800-900 r / min, 900-1000 r / min, 1000-1030 r / min, and 1030-1080 r / min. At least 8 oil quantity limit parameters corresponding to the boost air pressure are set in each speed interval.

5. A method for preventing overspeeding and black smoke emission from a four-stroke marine engine under all operating conditions, as described in claim 1, is characterized in that... In step S4, the electronic speed controller uses a PID control algorithm to adjust the fuel supply, and the adjustment response time does not exceed 100ms.

6. The method for preventing overspeeding and black smoke emission from a four-stroke marine engine under all operating conditions according to claim 1, characterized in that, In step S4, the electronic speed controller compares the real-time speed of the main unit with the preset safe speed range. When the real-time speed is 1080r / min±5r / min, it reduces the oil supply in advance.

7. The method for preventing overspeeding and black smoke emission from a four-stroke marine engine under all operating conditions according to claim 1, characterized in that, In step S5, the audible and visual alarm includes a sound alarm and a light alarm. The sound alarm has a decibel level of not less than 80dB, and the light alarm uses a red LED light. The audible and visual alarm will feed back abnormal data to the ship monitoring system.

8. The method for preventing overspeeding and black smoke emission from a four-stroke marine engine under all operating conditions according to claim 1, characterized in that, In step S6, the data storage module includes local storage and cloud backup. The local storage uses a solid-state drive, and the cloud backup uses an encrypted transmission method.

9. A method for preventing overspeeding and black smoke emission from a four-stroke marine engine under all operating conditions, as described in claim 1, is characterized in that... It also includes a filtering process for the host load feedback signal. After the boosted air pressure signal is acquired in step S1, the signal is filtered by a low-pass filter with a cutoff frequency of 10Hz.

10. A method for preventing overspeeding and black smoke emission from a four-stroke marine engine under all operating conditions, as described in claim 1, is characterized in that... It also includes a calibration step for the fuel quantity limit parameter, which is calibrated based on historical operating data, standard operating condition data, and manually input calibration parameters.

Images