一、 Industry background of monitoring the status of ship transmission chains
With the continuous development of the social economy, the development of the shipbuilding industry has been promoted. As an important mode of maritime transportation, ship transportation plays a positive role. For ships, their power equipment is the core and key to the entire operation of the ship. The failure of power equipment will directly affect the safety of the entire ship's navigation. Necessary status monitoring and fault analysis of the power equipment of ships are crucial to ensuring safe operation of the ship.
二、 Purpose of ship status monitoring
In the process of ship navigation, ship power equipment provides reliable support for safe navigation. The implementation of status monitoring and fault diagnosis can comprehensively grasp the operation of ship power equipment, timely discover hidden faults, and take effective measures to eliminate faults, reducing the probability of safety accidents during ship operation. In this situation, exploring the monitoring and fault diagnosis technology of ship power equipment has certain practical significance.
三、 Vibration based monitoring and diagnosis technology for ship power equipment
1. Vibration monitoring technology for ship power equipment based on industry standards
For ship power equipment, vibration monitoring technology is an effective way. In the actual monitoring process, based on the evaluation criteria of equipment status, with the support of vibration diagnosis, the root mean square value of total vibration speed, vibration intensity, and vibration magnitude are the main evaluation parameters. Combined with the specific type of ship power equipment, evaluation standards are selected and applied in a standardized manner, and the movement mechanism of equipment should be scientifically analyzed to improve the scientific and effective diagnosis.
2. Vibration monitoring and diagnosis method based on the fault mechanism of power equipment
In terms of diesel engine condition monitoring, vibration diagnosis technology is an effective way. Under the action of vibration method, the gap between the piston and the cylinder liner will change, which is manifested by the vibration characteristics of the cylinder liner. Under the transmission effect, the change in the gap between the cylinder liner and the piston can be predicted, comprehensively reflecting the impact of excitation force, and then judging the valve status through the surface vibration signal of the cylinder.In terms of gearbox vibration diagnosis, temperature and vibration are used to reflect the operating status of the gearbox, and the time-frequency components of the vibration signal are analyzed to further diagnose faults. The calculation of equipment failure frequency focuses on gears, rolling bearings, and rotors. By grasping the vibration mechanism of power equipment and understanding the characteristics of equipment failures, scientific treatment of vibration can be carried out.
四、 Vibration analysis method
This method utilizes the vibration signals generated by ship diesel engines during operation, and through testing, data analysis, and processing, grasps the status of internal components and conducts fault trend analysis and diagnosis. Its method has the characteristics of fast diagnostic speed, high accuracy, and the ability to achieve online diagnosis, and is widely used in ship power machinery.This method is currently mainly applied in the monitoring and diagnosis of ship power machinery and other equipment. (1) Vibration monitoring of piston cylinder liner wear. According to the vibration response of the body under different wear states of the piston cylinder liner, the peak power spectrum and total energy can be used as characteristic parameters to distinguish the wear state of the piston cylinder liner.
(2) Vibration monitoring of air valve leakage faults. Based on the time-domain waveform of the cylinder head vibration response, the timing pattern of the air valve, and the top dead center signal, the vibration response of the main excitation source can be identified from the vibration response on the surface of the cylinder head. The power spectrum of the vibration response on the surface of the cylinder head can be used to determine the leakage status of the gas valve.
(3) Vibration monitoring of wear faults in diesel engine main bearings. It is possible to perform power spectrum analysis on vibration signals and then perform cepstral analysis to determine the wear status of diesel engine main bearings.
五、 Ship status monitoring Senther Technology sensor products
1. Senther 372P high-temperature resistant charge output accelerometer:
The 372P series product is a high-temperature resistant piezoelectric accelerometer, characterized by the use of compressed ceramic crystals as sensitive components, with the characteristic of high-resolution output signals. This accelerometer is based on the characteristics of piezoelectric ceramics and outputs a charge signal through a low-noise cable, with the signal isolated from the casing.The shell is made of high-temperature alloy, and the sealing of the product is achieved through laser welding process; The output connector adopts a miniature glass insulated connector to meet the stability of the output when used in different environments.The bottom of the 372P product is equipped with 10-32 threaded holes for testing purposes, and triangular mounting through-hole feet are also provided for bolt installation. M4 screws can be used to fix the accelerometer to the tested object. The 372P series accelerometer has broadband response and high-temperature resistance, making it suitable for measuring dynamic acceleration and vibration in high-temperature environments.
2. Senther T223 industrial dual axis tilt sensor
T221 is a dual axis tilt sensor that can achieve precise output over a wide temperature range. Internally, high-speed microprocessors are used to linearly modulate signals and compensate for temperature. This product adopts full process calibration and can be customized with digital or analog outputs. It is mainly aimed at applications in platform calibration, robot control, flip protection, tilt alarm, and other fields.The fast response characteristics and high precision make this sensor the best choice for monitoring mobile platform devices. The built-in integrated high-order filter ensures signal quality and allows the sensor to be used in noisy environments (such as vibration environments).This series of products can adjust the sensor factory settings according to the application environment to provide optimal performance. Customization of measuring range, cables, and connectors can also be carried out according to on-site installation requirements. The sturdy aluminum alloy shell is resistant to oil, grease, and fuel erosion.
六、 The realization of safe navigation of ships cannot be achieved without the support of ship power equipment. Ships use diesel engines as the main power equipment, and gearboxes, air compressors, and other auxiliary power equipment as auxiliary power equipment. In order to promote the maximum value of ship power equipment, it is necessary to do a good job in condition monitoring and fault diagnosis, grasp the operation status of ship power equipment, so as to detect potential faults in the first time, take effective measures to solve problems, and ensure the safe operation of ship power equipment.
