Method for determining the shaft speed of a centrifugal compressor and diesel-generator

The output parameters of power plants, the shaft speed in particular, must be measured with high accuracy. The readings of standard frequency meters fail to satisfy such requirements, therefore it is necessary to use advanced methods. This paper describes an alternative method for determining the shaft speed of a centrifugal compressor and the crankshaft of a diesel generator using a Hall sensor. The Hall Effect was studied, the experiment was conducted and the experimental data were compared with the readings of standard measuring instruments. A measurement circuit was implemented for this purpose. The measurement circuit included a Hall sensor, an oscilloscope, and a power cell. Numerous measurements were taken to increase the accuracy of data collection. As a result, the optimum values of the gap setting (between the sensor and the closing element) were obtained, and the voltage values of the input signal were accurately displayed on the oscilloscope screen. The shaft speed of a centrifugal compressor and a diesel-electric power unit was measured. The experiment was conducted using the “DisCo” software and the “VM8020” oscilloscope. When taking readings from a standard frequency meter, the measurement error is 2%, whereas it was only 1% in the proposed measurement method. The experiment confirmed that this method is more accurate, simpler and more reliable in use. The advantage of the research is that it makes it possible to determine the crankshaft speed of the engine with high accuracy in order to make the adjustments on the power unit using the software and “VM8020” oscilloscope. We found the most acceptable solution for determining the exact shaft speed of the compressor and the crankshaft speed of the diesel unit. This method for determining the shaft speed can be used in any stationary plants.