Marine diesel engine shaft power monitoring sensor

Abstract

The invention relates to a marine diesel engine shaft power monitoring sensor, which comprises magneto-resistive sensors, measuring belts and peripheral circuits which are matched with the magneto-resistive sensors. When a transmission shaft rotates, the magneto-resistive sensor detects a variable magnetic field generated by a permanent magnet on a plastic block of the measuring belt and sine-like signals can be generated. Magneto-resistive sensors are symmetrically arranged at horizontal positions which are certainly distant from the radial directions of the measuring belts to output signals. The magneto-resistive sensors are made based on the magneto-resistive effect of magneto-sensitive resistance elements. Phase difference between the output signals of the two magneto-resistive sensors are extracted through signal processing to obtain a torque signal. The frequency of any one signal of the output signals of the two magneto-resistive sensors is calculated to obtain prime motor rotating speed, so as to obtain the value of shaft power. The marine diesel engine shaft power monitoring sensor has the advantages that the equipment structure is simple, the volume is small and the monitoring sensor is convenient to install; the sensitivity is high, the working frequency characteristic is stable and the anti-interference capability is strong; the measurement is accurate; and the shaft power and the rotating speed of the prime motor can be monitored in real time under the condition that the prime motor runs.

Description

technical field [0001] The invention relates to online monitoring of shaft power, in particular to a sensor for monitoring the shaft power of a marine diesel engine. Background technique [0002] The shaft power of marine diesel engine is an important parameter for ship delivery inspection, ship-engine-propeller matching and power plant performance monitoring and diagnosis during ship navigation. At present, the test methods at home and abroad are mainly strain-type torque test method and phase-difference torque test method. [0003] Strain torque testing methods are generally strain gauge method and magnetoelastic method. The strain gauge method uses electrical resistance strain gauges to measure the strain of the shaft system. Its installation requirements are relatively high, human factors are greatly affected, it is difficult to guarantee accuracy, and the service cycle and life are short. The magnetoelastic method is based on the piezomagnetic effect of ferromagnetic ...

AI Technical Summary

Problems solved by technology

The steel string method detects the phase difference through the frequency change of the steel string sensor. This method has high measurement accuracy, but there are many mechanical equipment, large volume, high cost, and inconvenient to carry and test.

The laser method is based on the Doppler effect, using equipment such as laser transmitters and receivers to detect the phase difference of electromagnetic sensor signals. It has high measurement accuracy and is easy to operate, but it requires a light source.

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