Method for transforming harbor tug generator started by pneumatic motor instead of electricity

Abstract

The invention relates to the technical field of ship auxiliary machinery, discloses a port tug generator transformation method with a pneumatic motor replacing electric starting, and aims to solve the problems that an existing electric starting system is high in failure rate and maintenance cost and difficult in cold starting. The method comprises the steps that a pneumatic starting system composed of a high-pressure energy storage unit, a flexible starting execution unit, an exhaust gas utilization and health diagnosis unit and a cooperative control unit is installed; and redundant compressed air of the main engine is used as a power source. A cooperative control unit of the system controls the starting process in a self-adaptive mode based on the temperature of a generator, and low-torque flexible meshing and torque smooth climbing are achieved so as to protect a mechanical structure; meanwhile, low-temperature exhaust exhausted after starting is used for preheating lubricating oil of the generator, and the cold starting performance is effectively improved; and during the standby period of the equipment, periodic micro-start operation is executed and the exhaust gas temperature is analyzed, so that health diagnosis and early warning of lubrication and air tightness of the generator are realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of marine auxiliary machinery, in particular to a method for modifying a port tug generator with a pneumatic motor instead of an electric starter. BACKGROUND

[0002] In the power system of a port tug, the auxiliary generator set is one of the key equipment, responsible for providing continuous and stable power supply for the navigation system, communication equipment, deck machinery and living facilities of the ship when the main engine is in low load, idle speed or shutdown state. Its reliability of operation is directly related to the safety and efficiency of the tug operation.

[0003] Currently, such auxiliary generator sets generally use an electric starting system. The system is usually composed of a battery pack, a DC starter motor, and corresponding relays and control circuits. The electric energy stored in the battery drives the starter motor, thereby driving the generator to reach the ignition speed.

[0004] However, this traditional electric starting scheme faces a series of inherent technical limitations in the specific application scenario of port tugs. The working environment of port tugs usually has high humidity and high salt fog, which poses a challenge to the long-term operation of the electric starting system. Electrical contacts are prone to oxidation, and the insulation performance of the circuit will decrease over time, and the performance of the battery will fluctuate due to changes in environmental temperature and charging and discharging state. These factors together lead to an increase in system failure rate and an increase in unplanned downtime. In order to maintain the availability of the system, periodic component inspection and replacement are required, especially for the battery and the starter motor, which directly increases the maintenance workload and operating costs of the ship.

[0005] In addition, the starting torque provided by the electric starting system is directly subject to the electrochemical state of the battery. At low temperatures, the effective discharge capacity and output current of the battery will be significantly reduced. At the same time, the viscosity of the generator's lubricating oil increases, causing its rotational resistance to rise. The superposition of these two effects reduces the certainty of successfully starting the generator in a low-temperature environment. The existing system usually applies a fixed, large impact torque directly to the gear during starting, lacking fine control of the meshing process and torque size, which can cause mechanical wear to the gear ring over time.

[0006] Finally, the existing electric starting system usually lacks monitoring and feedback mechanisms for its health status or starting process. Failures are often discovered after they occur, i.e., when the starting fails, which cannot provide early warning information to support preventive maintenance and does not have the ability to actively assess the mechanical state of the generator. SUMMARY

[0007] The technical problems to be solved by the present application are that the electric starting system for the port tug generator in the prior art has reliability problems and electric spark safety hazards caused by corrosion of electrical components in a high-salt and high-humidity environment, and the conventional pneumatic starting system has technical defects of high energy consumption, large mechanical impact in the starting process, and ice formation at the exhaust port caused by low-temperature and poor gas.

[0008] To solve the above technical problems, the present application provides a port tug generator modification method of replacing electric starting with a pneumatic motor, which is applied to a port tug containing a main engine and a generator.

[0009] The technical scheme provided by the present application is as follows:

[0010] A port tug generator modification method of replacing electric starting with a pneumatic motor, comprising the following steps:

[0011] S1, disassemble the original electric starting system of the generator composed of a storage battery and an electric starting motor;

[0012] S2, install and mechanically couple a set of pneumatic starting system on the generator, the pneumatic starting system comprising a high-pressure energy storage unit, a flexible starting execution unit, and a cooperative control unit, wherein the flexible starting execution unit comprises a two-stage torque adaptive pneumatic motor and a servo proportional valve;

[0013] S3, establish pneumatic connection between the high-pressure energy storage unit in the pneumatic starting system and the main engine of the port tug, so as to charge the compressed air generated by the main engine into the high-pressure energy storage unit;

[0014] S4, connect the exhaust port of the flexible starting execution unit in the pneumatic starting system to the lubricating oil circuit or oil sump of the generator through a waste gas utilization and health diagnosis unit to establish a heat exchange path;

[0015] S5, configure the cooperative control unit in the pneumatic starting system, so that the cooperative control unit cooperatively controls the energy acquisition process of the main engine, the starting process of the flexible starting execution unit, and the heat exchange process of the waste gas utilization and health diagnosis unit.

[0016] Preferably, the control of the cooperative control unit on the energy acquisition process specifically comprises:

[0017] continuously monitoring the working condition of the main engine, and when it is monitored that the main engine is in a steady working condition or a braking condition, and the pressure in the high-pressure energy storage unit is lower than a preset target pressure, obtaining compressed air from the main engine via the pneumatic connection.

[0018] In one specific embodiment, the control of the starting process by the cooperative control unit specifically includes:

[0019] In response to a starting instruction of the generator, performing a starting process based on temperature self-adaptation, the operation of the starting process being: first detecting the temperature of the body or lubricating oil of the generator; then self-adaptively determining starting parameters for the subsequent process according to the detected temperature; and finally driving the flexible starting execution unit to successively complete a low-torque engagement stage and a torque ramp-up stage according to the determined starting parameters.

[0020] Further, the starting parameters include a torque size for the low-torque engagement stage and a rotating speed ramp-up curve for the torque ramp-up stage.

[0021] In a more specific embodiment, the torque ramp-up stage specifically is:

[0022] The cooperative control unit controls the servo proportional valve in a closed loop based on the actual rotating speed feedback of the generator, so that the rotating speed of the generator accurately follows the rotating speed ramp-up curve until the ignition rotating speed is reached. The control signal output of the closed loop control can be described by the following formula:

[0023] U valve (t) = PID(ω target (t) - ω gen (t));

[0024] Wherein:

[0025] U valve (t) is the control signal applied to the servo proportional valve at time t;

[0026] PID(·) represents a standard proportional, integral, and differential controller algorithm;

[0027] ω target (t) is the rotating speed value on the preset target rotating speed ramp-up curve at time t;

[0028] ω gen (t) is the actual rotating speed value of the generator at time t fed back by a sensor. Preferably, the control of the heat exchange process by the cooperative control unit specifically includes:

[0029] In the starting process, the low-temperature exhaust gas flow discharged by the flexible starting execution unit is guided through the heat exchange passage to preheat the low-temperature exhaust gas by the temperature of the generator lubricating oil and to heat buffer the lubricating oil by the low-temperature exhaust gas.

[0030] In one embodiment, the cooperative control unit configured in step S5 has an integrated operation logic further comprising a standby maintenance mode activated after the generator is in a shutdown state for a preset time length.

[0031] Further, the operation logic of the standby maintenance mode is specifically:

[0032] The cooperative control unit periodically drives the flexible starting execution unit to rotate the generator at a preset extremely low torque and speed to pre-establish a lubricating oil film on the key friction pair surface of the generator.

[0033] In one specific embodiment, the cooperative control unit further performs the following diagnostic operation each time the operation of periodically rotating the generator is performed:

[0034] The diagnostic principle can be described by the following formula:

[0035] ΔT diag = T exhaust -g(μ base ,L base ,C sys );

[0036] Wherein:

[0037] ΔT diag is the diagnostic deviation value, and when the absolute value thereof exceeds a preset threshold value, the system is determined to be abnormal;

[0038] T exhaust is the actual exhaust gas outlet temperature measured by the sensor;

[0039] g(·) is a reference function model representing the heat exchange characteristics of the system;

[0040] μ base is the reference viscosity parameter of the lubricating oil in a healthy state;

[0041] L base is the reference sealing factor of the pneumatic system in a healthy state;

[0042] C sysis a set containing ambient temperature and other known system parameters.

[0043] Preferably, the two-stage torque adaptive pneumatic motor installed in step S2 comprises a low-torque power component and a high-torque power component, and the cooperative control unit is configured to:

[0044] only the low-torque power component is enabled in the low-torque engagement stage, and the high-torque power component is enabled according to the load requirement in the torque climbing stage.

[0045] The present application provides a method for modifying a harbor tug generator by replacing an electrically started pneumatic motor. The method has the following beneficial effects:

[0046] 1. The present application establishes pneumatic connection between the high-pressure energy storage unit and the main engine of the harbor tug, and configures a cooperative control unit to obtain compressed air under stable operation or braking conditions of the main engine. This method eliminates the need for an independent air compressor, reducing additional energy consumption of the system. At the same time, by removing the original battery and electric starting motor, the potential risk of starting failure caused by corrosion or short circuit of electrical components in a high-salt and high-humidity environment is eliminated.

[0047] 2. The present application configures a cooperative control unit to drive a flexible starting execution unit to perform a starting process in a low-torque engagement stage and a torque climbing stage, avoiding the instantaneous large torque impact during the engagement and acceleration process of the starting gear and the generator flywheel ring. In addition, by activating a standby maintenance mode after the generator has been stopped for a long time, the generator is driven at a very low torque to pre-establish a lubricating oil film, which reduces cold start wear caused by lack of lubrication.

[0048] 3. The present application sets up a waste gas utilization and health diagnosis unit to guide the low-temperature waste gas discharged by the flexible starting execution unit into a heat exchange passage established with the generator lubricating oil circuit, preheats the waste gas using the temperature of the lubricating oil, eliminates the risk of pipeline icing caused by direct discharge of waste gas, and at the same time, using the same physical structure, the method realizes the state evaluation of the viscosity of the lubricating oil or the sealing performance of the pneumatic system by monitoring the change of the waste gas outlet temperature in the standby maintenance mode, increasing the maintainability of the system. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 is a structural diagram of the pneumatic starting system of the harbor tug generator of the present application;

[0050] Figure 2 is a method flowchart of an embodiment of the present application;

[0051] Figure 3 is an energy acquisition logic flowchart of the cooperative control unit of the present application;

[0052] Figure 4 The start-up process control logic flow chart for the cooperative control unit of the present application;

[0053] Figure 5 The standby maintenance and health diagnosis logic flow chart for the cooperative control unit of the present application. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the specification of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0055] Refer to the drawings Figure 1 , Figure 1 It is a structural schematic diagram of the pneumatic starting system for the harbor tug generator according to the present application. The system provided by the embodiment is a system for performing a harbor tug generator modification method of replacing electric starting with a pneumatic motor. After the modification is completed, the system mainly includes a high-pressure energy storage unit 10, a flexible starting execution unit 20, a waste gas utilization and health diagnosis unit 30, and a cooperative control unit 40.

[0056] The high-pressure energy storage unit 10 includes a gas storage tank 11 for storing compressed air, a pressure sensor 12 installed on the gas storage tank 11 for measuring the internal pressure, and a safety valve 13 for overpressure protection. The volume and pressure resistance level of the gas storage tank 11 are selected according to the model and starting air consumption of the generator to be started.

[0057] The flexible starting execution unit 20 includes a two-stage torque adaptive pneumatic motor 21 and a servo proportional valve 22. The internal structure of the two-stage torque adaptive pneumatic motor 21 includes a low-torque power assembly 211 and a high-torque power assembly 212, and the two power assemblies can be independently or combined controlled by the cooperative control unit 40. The servo proportional valve 22 is connected with the air inlet of the two-stage torque adaptive pneumatic motor 21, used to receive the electric control signal from the cooperative control unit 40, and accurately adjust the pressure and flow of the compressed air supplied to the pneumatic motor 21 according to the signal.

[0058] The physical structure of the waste gas utilization and health diagnosis unit 30 is a hollow jacket, the inner wall of which is installed in close contact with the outer wall of the lubricating oil sump of the generator, forming a heat exchange interface. The inlet of the unit is connected with the exhaust manifold of the flexible starting execution unit 20, and the outlet thereof leads to the atmosphere outside the cabin. A high-precision temperature sensor 31 is installed at the final exhaust port of the waste gas utilization and health diagnosis unit 30.

[0059] The cooperative control unit 40 is a programmable logic controller (PLC) or embedded microprocessor (MCU) which contains a central processing unit, memory and multiple input / output interfaces inside. The memory is solidified with program codes for implementing all the operation logic of the method of the present application.

[0060] After the modification, the connection relationship between the above-mentioned units is as follows:

[0061] The gas inlet of the high-pressure energy storage unit 10 is connected to the supercharged air pipe or the control pipe of a specific cylinder of the main engine of the harbor tug through a high-pressure gas pipe controlled by an intelligent flow valve group. The gas outlet of the high-pressure energy storage unit 10 is connected to the inlet of the servo proportional valve 22 in the flexible starting execution unit 20 through a pipe.

[0062] The output shaft of the flexible starting execution unit 20 is mechanically coupled to the flywheel ring of the generator through a starting gear to transmit the starting torque. The exhaust port of the flexible starting execution unit 20 is connected to the inlet of the exhaust gas utilization and health diagnosis unit 30 through a pipe.

[0063] The input interfaces of the cooperative control unit 40 are respectively electrically connected to the pressure sensor 12 of the high-pressure energy storage unit 10, the temperature sensor 31 of the exhaust gas utilization and health diagnosis unit 30, a sensor group for monitoring the working condition of the main engine (such as a speed sensor and a load sensor), and a sensor for monitoring the speed and temperature of the generator. The output interfaces of the cooperative control unit 40 are respectively electrically connected to the servo proportional valve 22 and the intelligent flow valve group for controlling the gas extraction from the main engine.

[0064] The cooperative control unit 40 is configured to generate and output control signals based on the input signals through internal program logic operations. For example, the closed-loop control logic of the servo proportional valve 22, the control signal output of which can be described by the following formula:

[0065] U valve (t) = PID(ω target (t) - ω gen (t));

[0066] Wherein, U valve (t) is the control signal applied to the servo proportional valve 22 at time t; PID(·) represents the proportional, integral and differential controller algorithm; ω target (t) is the target speed value stored in the cooperative control unit 40 at time t; ω gen (t) is the actual speed value fed back by the generator speed sensor at time t.

[0067] For another example, the logic operation for performing health diagnosis can be described by the following formula:

[0068] ΔT diag = T exhaust - g(μ base , L base , C sys );

[0069] wherein ΔT diag is the diagnostic deviation value calculated by the coordinated control unit 40; T exhaust is the exhaust gas outlet temperature measured in real time by the temperature sensor 31; g(·) is a reference function model, solidified in the memory of the coordinated control unit 40, which represents the heat exchange characteristics in the system health state; μ base and L base are respectively the reference lubricating oil viscosity parameter and the reference system tightness factor stored in the model; C sys is a set containing other known system parameters such as the ambient temperature.

[0070] With reference to the attached Figure 2 , Figure 2 is a flow chart of the method according to an embodiment of the present application. This embodiment describes in detail the specific steps of a method for the retrofitting of a harbor tug generator with a pneumatic motor in place of the electric starter.

[0071] The first step (S1) of the method is the removal of the original electric starter system of the generator. This step comprises: first, disconnecting and removing the main power supply cable connected to the electric starter motor of the generator and its connection to the battery pack. Subsequently, disassembling and removing the electric starter motor assembly fixed to the generator body. Finally, removing the control circuit related to the original electric starter system, including the signal line from the bridge or local control panel to the starter relay, and the excitation line from the relay to the electric starter motor, thus completely removing all the physical components of the original electric starter system from the harbor tug.

[0072] The second step (S2) of the method is to install and mechanically couple a pneumatic starting system to the generator. The specific operation of this step is as follows: first, fix the flexible starting execution unit 20 to the generator body through a customized mounting bracket. The installation position should be selected to ensure that the output axis is accurately aligned with the meshing position of the flywheel ring gear. The customized mounting bracket is designed to fully consider the vibration characteristics of the generator during operation. It contains reinforcing ribs and is fixed using high-strength bolts to ensure that the flexible starting execution unit 20 maintains a stable relative position during ship navigation and generator operation. Then, align the starting gear of the unit with the flywheel ring gear, adjust the mounting bracket until the axial and radial clearances of the two meet the preset assembly tolerance. At the same time, install the high-pressure energy storage unit 10 on a fixed base in the engine room that has sufficient load-bearing capacity, and install the cooperative control unit 40 in the control box that is convenient for wiring and can avoid high temperature and severe vibration.

[0073] The third step (S3) of the method is to establish pneumatic connection between the high-pressure energy storage unit 10 in the pneumatic starting system and the main engine of the harbor tug. The specific operation of this step is as follows: draw a gas inlet from the intake manifold of the main engine (after the turbocharger and before the cylinder) and install a one-way valve at the gas inlet to prevent gas backflow. As an alternative, the gas inlet can also be set on the gas storage manifold of the main engine's compressed air system (such as the auxiliary air system for pneumatic brakes or air valve drive). The advantage of choosing this scheme is to avoid direct modification of the intake system, but correspondingly, the energy acquisition logic of the cooperative control unit 40 must be adjusted: the monitoring of the main engine auxiliary air system pressure must be increased, and the priority of the air supply operation must be set to ensure that the pneumatic needs of the main engine's own system are met first. Then, connect the gas inlet to the inlet of an electromagnetic valve (i.e., intelligent shunt valve group) controlled by the cooperative control unit 40 through a high-pressure-resistant metal pipeline. The outlet of the electromagnetic valve is connected to the gas inlet of the high-pressure energy storage unit 10 through a pipeline.

[0074] The fourth step (S4) of the method is to connect the exhaust port of the flexible starting execution unit 20 in the pneumatic starting system to the lubricating oil sump of the generator through a exhaust gas utilization and health diagnosis unit 30 to establish a heat exchange path. The specific operation of this step is as follows: tightly fix the exhaust gas utilization and health diagnosis unit 30 (i.e., hollow jacket) to the outer surface of the generator lubricating oil sump, and apply thermal conductive silicone grease between the contact surfaces to reduce the contact thermal resistance. Then, use low-temperature-resistant flexible or rigid pipelines to connect the exhaust manifold of the flexible starting execution unit 20 to the inlet of the exhaust gas utilization and health diagnosis unit 30, and then connect the outlet of the unit to the safe area outside the engine room for exhaust.

[0075] The fifth step (S5) of the method is to configure the cooperative control unit 40 in the pneumatic starting system. This step is a non-physical installation step, and its operation is to load the firmware program containing all the control logic of the application (including energy acquisition logic, starting control logic, standby maintenance logic, and health diagnosis logic) into the memory of the cooperative control unit 40 through a dedicated programming interface. During the configuration process, a series of initial parameters need to be set, such as the target pressure upper and lower limit values set for the high-pressure energy storage unit 10, the generator shutdown time threshold required to trigger the standby maintenance mode, the initial parameters of the reference temperature model used for health diagnosis (such as μ base ,L base ), and the rotational speed climb curve data table preset for different working conditions (such as cold machine and hot machine). After the configuration is completed, the cooperative control unit 40 has the ability to automatically perform all subsequent cooperative control operations based on real-time sensor inputs.

[0076] Referring to the accompanying Figure 3 to the accompanying Figure 5 , these drawings are schematic diagrams of the internal operation logic and workflow of the cooperative control unit 40 according to an embodiment of the application. After step S5 of the method of the application is performed, the cooperative control unit 40 is configured to automatically perform the following control processes.

[0077] Control logic of the energy acquisition process:

[0078] Referring to the accompanying Figure 3 , the cooperative control unit 40 is configured to periodically perform an energy acquisition monitoring and decision-making cycle. First, the cooperative control unit 40 reads the pressure P tank of the pressure sensor 12 in the high-pressure energy storage unit 10 in real time and compares it with a preset target pressure value P target stored internally. At the same time, the cooperative control unit 40 receives and analyzes the working condition signals from the main engine of the harbor tug through the input interface.

[0079] When and only when both conditions are met, i.e., (1) P tank <P target and (2) the main engine is in a stable working condition (e.g., the rotational speed and load are stable within a preset interval for more than a certain time) or in a braking condition (e.g., an explicit signal is received from the ship braking system), the cooperative control unit 40 outputs a control signal to open the electromagnetic valve connecting the main engine and the high-pressure energy storage unit 10, and starts to acquire compressed air from the main engine. During the air charging process, the cooperative control unit 40 continuously monitors the value of P tank , and as soon as P tank is greater than or equal to P target , it immediately outputs a signal to close the electromagnetic valve, completing a cycle of energy acquisition.

[0080] Control logic of the starting process:

[0081] Refer to the attached Figure 4 When the cooperative control unit 40 receives the generator starting instruction sent from outside, it will strictly follow a programmed starting process.

[0082] The first step of the process is to make an adaptive decision of the state. The cooperative control unit 40 first reads the temperature T gen of the temperature sensor connected to the generator body or lubricating oil circuit. threshold Then, the temperature is compared with a preset cold, hot state judgment threshold T gen .

[0083] If T gen <T threshold , it is determined to be cold start; otherwise, it is hot start. According to the judgment result, the cooperative control unit 40 will retrieve the corresponding starting parameter set from its internal memory, including the target torque value T engage of the low torque engagement stage set for this state, and a speed climbing curve ω target (t) customized for this state. The parameters corresponding to the cold start usually have a higher T engage and a relatively flat ω target (t) curve.

[0084] The second step of the process is to execute the low torque engagement stage. The cooperative control unit 40 outputs an accurate, lower constant control signal to the servo proportional valve 22, and the amplitude of the signal is calibrated to be just enough to make the low torque power assembly 211 of the two-stage torque adaptive pneumatic motor 21 generate the target torque T engage . Under the drive of this torque, the starting gear slowly and smoothly moves forward and engages with the flywheel ring of the generator until the feedback signal of a limit switch or torque sensor confirms that the engagement is in place.

[0085] The third step of the process is to execute the torque climbing stage. After the engagement is completed, the cooperative control unit 40 immediately starts a closed-loop control cycle. In this cycle, it collects the actual speed ω gen (t) of the generator in real time and compares it with the current target speed ω target (t) obtained by looking up the selected curve, calculates the control error according to the PID control algorithm and generates a new control signal U valve (t) to continuously adjust the opening of the servo proportional valve 22. In this process, if the control unit 40 judges that the required torque exceeds the capacity range of the low torque power assembly 211 according to the acceleration of the speed, it will simultaneously enable the high torque power assembly 212 to provide additional driving force. This closed-loop control process continues until ωgen (t) reaching the preset ignition speed, at which the cooperative control unit 40 will stop outputting the control signal, close the servo proportional valve 22, and instruct the starting gear to return to the original position, and the starting process ends. The specific values of the three parameters P, I, and D in the PID control algorithm are determined in the debugging stage after the modification is completed, through multiple starting tests on the actual generator set, according to the system response characteristics, and are determined by experience or optimized by using an adaptive algorithm, to ensure good speed following performance under different loads and temperatures.

[0086] Control logic of standby maintenance and health diagnosis:

[0087] Referring to the accompanying drawings Figure 5 , the cooperative control unit 40 is also configured to execute a standby maintenance mode. A timer inside the cooperative control unit 40 continuously records the cumulative downtime t down of the generator. down When t maint exceeds a preset maintenance trigger duration threshold τ exhaust (e.g., 72 hours), the standby maintenance mode is automatically activated.

[0088] In this mode, the cooperative control unit 40 performs an oil film pre-establishment and health diagnosis cycle at a preset period (e.g., every 12 hours). In each cycle, the cooperative control unit 40 performs a micro-start operation, i.e., drives the generator to rotate slowly for a few turns at a very low preset constant torque. The purpose of this operation is to agitate the lubricating oil in the oil sump and bring it to the surfaces of key friction pairs such as cylinder walls, bearings, etc., to pre-establish a layer of lubricating oil film.

[0089] At the same time of performing the micro-start operation, the health diagnosis logic is synchronously executed. Since the air flow through the pneumatic motor is small and stable at this time, the cooperative control unit 40 accurately reads the temperature T sys of the exhaust gas at the outlet of the health diagnosis unit 30 using the temperature sensor 31. Then, it calls the internally stored reference temperature model g(·) to calculate the theoretical exhaust gas outlet temperature T base corresponding to the health status of the lubricating oil and the air tightness under the current working conditions (input the known environmental temperature and other parameters into the C exhaust set). The reference temperature model g(·) is obtained by performing the micro-start operation of standby maintenance multiple times at different environmental temperatures when the system is first installed and debugged and confirmed to be in a healthy state, and recording the exhaust gas outlet temperature T exhaustThen, with these collected data points, an empirical function model is established by polynomial fitting or neural network training method, which can accurately reflect the heat exchange characteristics of the system in a healthy state, and is solidified in the memory of the collaborative control unit 40. Finally, by calculating the deviation ΔT diag = T exhaust - T base of the actual value and the theoretical value, and judging whether its absolute value exceeds a preset alarm threshold, the diagnosis of abnormal lubricating oil viscosity or small leakage in the gas circuit system is realized. If the diagnosis result is abnormal, the collaborative control unit 40 will record the fault code and send a maintenance alarm to the ship monitoring system through its output interface.

Claims

1. A method of retrofitting a harbor tug generator with a pneumatic motor instead of an electric starter, characterized in that, The method is applied to a harbor tug comprising a main engine and a generator, and comprises the following steps: S1. removing the original electric starting system of the generator, which is composed of a storage battery and an electric starting motor; S2. installing and mechanically coupling a pneumatic starting system to the generator, the pneumatic starting system comprising a high-pressure energy storage unit, a flexible starting execution unit, and a cooperative control unit, wherein the flexible starting execution unit comprises a two-stage torque adaptive pneumatic motor and a servo proportional valve; S3. establishing pneumatic connection between the high-pressure energy storage unit in the pneumatic starting system and the main engine of the harbor tug, so as to charge the high-pressure energy storage unit with compressed air generated by the main engine; S4. connecting the exhaust port of the flexible starting execution unit in the pneumatic starting system to the lubricating oil circuit or oil sump of the generator through a waste gas utilization and health diagnosis unit, so as to establish a heat exchange passage; S5. configuring the cooperative control unit in the pneumatic starting system, so that the cooperative control unit cooperatively controls the energy acquisition process of the main engine, the starting process of the flexible starting execution unit, and the heat exchange process of the waste gas utilization and health diagnosis unit.

2. A method of retrofitting a harbor tug generator with a pneumatic motor in place of an electric starter according to claim 1, characterized in that, The control of the energy acquisition process by the cooperative control unit specifically comprises: monitoring the working condition of the main engine, and acquiring compressed air from the main engine via the pneumatic connection when the main engine is in a stable working condition or a braking condition and the pressure in the high-pressure energy storage unit is lower than a preset target pressure.

3. A method of retrofitting a harbor tug generator with a pneumatic motor in place of an electric starter according to claim 1, wherein, The control of the starting process by the cooperative control unit specifically comprises: in response to a generator starting instruction, performing a temperature-adaptive starting process, the operation of which is as follows: first, detecting the temperature of the body or lubricating oil of the generator; then, adaptively determining starting parameters for the subsequent process according to the detected temperature; and finally, driving the flexible starting execution unit to successively complete a low-torque engagement stage and a torque climbing stage according to the determined starting parameters.

4. The method of retrofitting a harbor tug generator from electric to pneumatic motor starting according to claim 3, wherein, The starting parameters include the torque size for the low-torque engagement stage and the rotating speed climbing curve for the torque climbing stage.

5. A method of retrofitting a harbor tug generator from electric starting to pneumatic motor starting according to claim 4, wherein, The torque climbing stage specifically comprises: The cooperative control unit controls the servo proportional valve in a closed loop based on the actual rotating speed feedback of the generator, so that the rotating speed of the generator accurately follows the rotating speed climbing curve until the ignition rotating speed is reached.

6. A method of retrofitting a harbor tug generator with a pneumatic motor in place of an electric starter according to claim 1, wherein, The control of the heat exchange process by the cooperative control unit specifically comprises: in the starting process, guiding the low-temperature waste gas discharged by the flexible starting execution unit to flow through the heat exchange passage, so as to preheat the low-temperature waste gas using the temperature of the generator lubricating oil and heat buffer the lubricating oil using the low-temperature waste gas.

7. A method of retrofitting a harbor tug generator with a pneumatic motor in place of an electric starter according to claim 1, wherein, The operation logic of the cooperative control unit configured in step S5 further comprises a standby maintenance mode, which is activated after the generator is in a shutdown state for a preset time length.

8. A method of retrofitting a harbor tug generator from electric starting to pneumatic motor starting according to claim 7, wherein, The operation logic of the standby maintenance mode specifically comprises: The cooperative control unit periodically drives the flexible starting execution unit to rotate the generator with preset extremely low torque and rotating speed, so as to pre-establish a lubricating oil film on the key friction pair surface of the generator.

9. A method of retrofitting a harbor tug generator from electric starting to pneumatic motor starting according to claim 8, wherein, In each execution of the operation of periodically rotating the generator, the cooperative control unit further executes the following diagnostic operation: By monitoring the exhaust gas outlet temperature flowing through the exhaust gas utilization and health diagnosis unit and comparing the monitored exhaust gas outlet temperature with a reference temperature model, the lubricating oil viscosity state of the generator or the sealing of the pneumatic starting system is diagnosed.

10. A method of retrofitting a harbor tug generator with a pneumatic motor in place of an electric starter according to claim 1, wherein, The internal part of the two-stage torque self-adaptive pneumatic motor installed in step S2 comprises a low torque power component and a high torque power component, and the cooperative control unit is configured to: only enable the low torque power component in the low torque engagement stage, and enable the high torque power component according to the load requirement in the torque climbing stage.

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