Shaft power meter

Briefly overview of shaft power meter definition. Describe its working mode and parameter calculation formula. The necessity of shaft power detection is emphasized.

1.Definition

The shaft power meter can be used to monitor the real torque and power on the ship's propulsion shaft. By measuring the shaft power of the main engine under different working conditions, the matching between hull, main engine and propeller can be understood. When the machine is not matched, the host may not fully use its rated power, and serious overload may occur. With the development of large-scale ships and automation, the efficiency and economy of ships have become important indicators of shipbuilding. As an important means to calculate the conversion efficiency, shaft power measurement has become an important parameter for the ship and the shipowner to accept the newly built ship.

2.How does the shaft power meter work & Calculation formula？

Marine shaft power meters measure real-time torque (torque), speed and power output on the drive shaft. When torque is applied to the shaft, a small amount of strain or "distortion" occurs on the shaft surface. Shaft power meters use sensors to measure this strain on the shaft and transmit the signal to a fixed receiver, which processes and calculates torque values based on the mechanical characteristics of the shaft. The amount of torque is then combined with speed (usually using a built-in tachometer) to calculate power. Power is a simple product of torque, speed and coefficient. Because of the close relationship between power and torque, the name "shaft power meter" is often used interchangeably with "shaft torque meter" or "shaft torque meter".

3.Shaft power detection is necessary

Engine power is usually calculated based on bench tests or engine performance curve data established by the manufacturer. The motor, on the other hand, relies on measuring voltage x current and then calculating torque data from load data. The torque is derived indirectly by both methods. While in most cases these methods give a good indication of torque on the shaft, a "good indication" of torque cannot be equated with the true mechanical torque measured by the sensor.

4.The Marine shaft power meter system consists of three main components:

1) Sensor 2) transmitter 3) receiver. The purpose of the sensor is to convert the distortion on the shaft into an electrical signal. The transmitter energizes the sensor and transmits the signal from the sensor. The main job of the receiver is to receive the signal from the transmitter, process the signal and output it in a data output format acceptable to the end user. Marine shaft power integrated ship bridge system. These indicators are analyzed in combination and can be used in conjunction with other accessories. Such as fuel gauge, efficiency to calculate the effect of the engine or fault diagnosis.

5.Shaft power meter type

The main difference between the various types of permanent shaft power meters is the type of sensor. The most common are: optical sensors, magnetic sensors and strain gauge sensors.