Results 1 - 10 of 9175
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[en] A program of steady-state and transient performance analysis for a 200kW-class small turboshaft engine with free power turbine was developed. An existing turbojet engine was used for the gas generator of the developed turboshaft engine, which was modified to satisfy performance requirements of this turboshaft engine. To verify the accuracy of steady-state performance program for this engine: the program was applied to the gas turbine test unit of the same type, and the analysis results were compared with experimental results. The developed transient performance analysis program using the CMF(Constant Mass Flow) method was utilized to analyze the cases of step increase and ramp increase of the fuel
[en] In the purpose of discovering causes of high vibrations and long cracks on stay vanes of the turbines at HPP 'Iron Gate I' measuring of stresses in the upper zone and in the lower zone along the stay ring are completed. Investigations performed some 20 years ago, in order to find out the excitation of vibrations, included measurements of the pressure along the trailing edge and stresses on stay vanes. The main frequency was about 36 Hz, which is very close to the natural frequencies of some stay vanes. It was concluded that there were two excitations, one belonging to Karman vortexes and the other to attack flow of the guide vanes, both with very close frequencies, causing beating oscillations. Modification of the stay vanes was made by grinding of the convex part of the trailing edges until half-circular concave of the same radius of 25 mm was reached. On site measurements performed at one unit, with original and modified trailing edge, with the same measuring devices, at the same measuring points and at the nearly same operating regimes. Influence of the modification on the static and dynamic stresses of the stay vanes, as well as their frequencies of the oscillations, is shown in the paper.
[en] This paper presents a numerical analysis of flow in a 2 jet Pelton turbine with horizontal axis. The analysis was done for the model at several operating points in different operating regimes. The results were compared to the results of a test of the model. Analysis was performed using ANSYS CFX-12.1 computer code. A k-ω SST turbulent model was used. Free surface flow was modelled by two-phase homogeneous model. At first, a steady state analysis of flow in the distributor with two injectors was performed for several needle strokes. This provided us with data on flow energy losses in the distributor and the shape and velocity of jets. The second step was an unsteady analysis of the runner with jets. Torque on the shaft was then calculated from pressure distribution data. Averaged torque values are smaller than measured ones. Consequently, calculated turbine efficiency is also smaller than the measured values, the difference is about 4 %. The shape of the efficiency diagram conforms well to the measurements.
[en] The turbine startup is a transient event generating high amplitude stress cycles in runner blades which might reduce significantly the life expectancy of the runner. Our goal is to use the increased range of possibilities offered by newer governing system to optimize the wicket gates control pattern in order to reduce the amplitude of the strain transient in the runner blade during startup. In this paper, we present our success in defining an optimal wicket gates control pattern for the startup of a newly commissioned propeller runner
[en] Main equipment of thermal power plant, such as boiler and turbine, are designed and manufactured by domestic techniques. But the special equipments monitoring the operation status of these main facilities are still dependent upon foreign technology. Therefore, so as to develop boiler tube leak detection system, we performed studying on manufacturing, installation in site, Acoustic Emission (AE) signal analysis and discrimination etc. As result of studying on boiler tube leak detection using AE, we conformed that diagnosis for boiler tube and computerized their trend management is possible, and also it is expected to contribute to safe operation of power plant facilities
[en] The possibility of adjusting of the jet-reactive turbine’s head parameters through changing of mass-flow of the working body with the help of adjustable feed-in nozzle is examined. The mass-flow coefficient of the feed-in nozzle is determined experimentally. (paper)
[en] The paper concerns axial water turbine of power equal to 1 kW. The example of axial water turbine constructional calculations was provided, as well as turbine rotor construction with NACA profile blades. The laboratory test rig designed and built to perform measurements on pico turbine was described. The turbine drove three-phase electrical generator. On the basis of highest efficiency parameters, pico turbine basic characteristics were elaborated. The experimental research results indicated that pico turbine can achieve maximum efficiency close to the values of larger water turbines. (paper)
[en] This book tells of definition and classification of fluid machinery, energy equation of incompressible fluid, principle of momentum, classification and structure of pump, size, safety of centrifugal pump, theory and operation of contraction pump, reciprocating pump, rotary pump, special pump, using of water power, classification of water turbine, impulse water turbine, reaction water turbine, pump water turbine, liquid movement apparatus, fluid type control machinery and solid and gas type pneumatic machine.
[en] High quality of turbine babbit bearing has to be maintained for smooth operation of power plants. So in the research center of the Korea Electric Power Company, Ultrasonic testing has been performed on the spare part of babbit bearing during past ten years. Since separation between babbit bearing and base metal was seen for most of the bearings in stock, investigation has begun in order to see the effect on temperature and humidity variation of the separation, and thus searching for the optimum storage method
[en] An optical instrument for the differential measurement of turbine palettes radial dimensions was designed, realized, characterized and successfully used in the field. The measurement system is used for the monitoring of the radial length of the rotor palettes, during final turbine rectification. The developed instrument provides a radial size measurement accuracy better than 10 µm, which is quite adequate for this application. This paper describes the design and realization of this optical sensor, and the in-field measurements obtained during the turbine grinding process at Ansaldo ENergia in Genova (IT)