A Sensitivity Measuring Device of Horizontal Hydrostatic Bearing System for a Bulb-type Model Turbine Test |
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학술지명 AFORE2015
저자 김현석,김영준,이교현,조용,권성일
발표일 2015-11-06
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Small scale model testing is one of the important process for a large hydraulic turbine system. During the test, various measuring instruments such as flow meters, differential pressure gauges, load cells, and RTD sensors are used to acquire the precise measurement data after the calibration test for each instrument. For an efficiency test, hydraulic power can be measured by acquiring discharge flow rate and total pressure between inlet and draft tube, and the power of the turbine can be measured by acquiring the rotating speed and the torque. In general, torque of a hydraulic turbine is transmitted to a dynamo-system, in which torque can be measured, via mechanical systems such as bearings, seals, and gears. In order to acquire precise torque value, measured torque at a dynamo-system should be add small torque of mechanical loss generated from bearings and gears. In case of a bulb-type model turbine, precise turbine torque including the relevant total friction torque can be measured if a horizontal hydrostatic bearing is installed in a bulb of a model turbine. To prevent incorrect functioning of a hydrostatic bearing, its sensitivity should be in a range referred in a model test standard. A sensitivity measuring device is designed to indicate very small torque in various thrust load conditions. In the device, an additional hydrostatic bearing is applied to produce the thrust force in frictionless condition. After a horizontal hydrostatic bearing system is developed soon, the sensitivity measuring test will be carried out in various thrust load conditions. |