Kaplan Type Research Articles

The effects of improvement of the main shaft on the operating conditions of the Agnew turbine

Agnew turbine is a 45° axial flow Kaplan type micro hydro. The turbine was designed by an ex-lecturer of the University of Glasgow, to operate without guide vanes. Later due to a joint research program between the Iranian Research Organization for Science and Technology (IROST) and the University of Glasgow it was developed to operate under low head and limited flow potentials in Iran. The original design of the main shaft of the turbine was supported by a bearing housing consisting of three bearings outside the main casing, leaving the rest of the shaft, hub and the runner without any supports inside the turbine .Later a suitable support near the runner and inside the casing was designed and installed. Standard turbine tests showed considerable improvements in operating characteristics of the turbine due to these design modifications. This paper presents details of these improvements and the related outcomes.

Pulsating turbulent flow in a straight asymmetric diffuser

Pulsating turbulent flow is studied for four regimes: steady, quasi-steady, relaxation, and quasi-laminar in a rectangular straight asymmetric diffuser, a generic model of the diffuser found at the end of most Kaplan and Francis type hydropower turbines. The flow entering the diffuser is a developing duct flow at Reynolds number 20 000, based on mean streamwise velocity and hydraulic diameter. The time averaged velocity and turbulent quantities are not affected by the forced oscillation. The regimes prevail in the diffuser, but are shifted due to the decreasing friction velocity. The oscillating quantities are affected by the adverse pressure gradient in the same way as the time averaged quantities, but with a decreasing effect for higher forcing frequencies. The amplitude of the oscillating wall shear stress is found to be signicantly lower than the Stokes solution in the quasi-laminar regime. The regime is confirmed by the behavior of several other quantities. The pressure recovery is found to be 30% higher in the relaxation regime than in the other regimes. Results are compared with experiments in channels and turbulent boundary layers, with and without an adverse pressure gradient, and with large-eddy simulations.

SALMONID SMOLT SURVIVAL RELATIVE TO TURBINE EFFICIENCY AND ENTRAINMENT DEPTH IN HYDROELECTRIC POWER GENERATION

ABSTRACT: The hypotheses that fish survival probabilities may be lower (1) at less than peak operating turbine efficiency; (2) at deeper entrainment depth; and (3) with the deployment of extended-length intake guidance screens, are not supported by results on yearling chinook salmon smolts (Oncorhynchus tshawytscha) at Lower Granite Dam, Snake River, Washington. Estimated 96 h survival probabilities for the six test conditions ranged from 0.937 to 0.972, with the highest survival at turbine operating towards the lower end of its efficiency. A blanket recommendation to operate all Kaplan type turbines within ± 1 percent of their peak efficiency appears too restrictive. Cavitation mode survival (0.946) was comparable to that at peak operating efficiency mode (0.937), as was the survival between upper (0.947) and mid depths (0.937). Survival differed only slightly among three turbine intake bays at the same depth (0.937 to 0.954), most likely due to differential flow distribution. Extended-length intake fish guidance screens did not reduce survival. However, the sources of injury somewhat differed with depth; probable pressure and shear-related injuries were common on fish entrained at mid-depth, and mechanically-induced injuries were common at upper depth. Operating conditions that reduce turbulence within the turbine environment may enhance fish survival; however, controlled experiments that integrate turbine flow physics and geometry and the path entrained fish traverse are needed to develop specific guidance to further enhance fish passage survival.

Mechanisms for photochemical hydration of N-substituted pyridinium ions

Photoinduced hydration of some pyridinium ions has been studied. Several pathways in the photohydration of quaternary pyridinium ions were observed. The substituents, especially at the nitrogen atom of the ring profoundly affect the reaction pathway, i.e. N-benzyl- and N-phenyl-pyridinium ions gave ring-cleaved ω-aminoaldehydes [e.g.(3)]via 2-hydroxy-1,2-dihydropyridines [e.g.(2)](Type A), while N-methyl isomers afforded azabicyclo[3.1.0]hex-3-en-2-ols (14) as reported by Kaplan (Type B). But exceptionally, N-methyl-3-carbamoylpyridinium ion (11h), which has an electron-withdrawing group, undergoes the Type A reaction. The Type A reaction clearly predominates over Type B, since nucleophiles can add in the dark to a pyridinium ion possessing an appropriate electron-withdrawing group in the ring.

Vibration and Noise in Hydraulic Turbines and Pumps

This paper describes numerous examples where objectionable vibration due to various causes occurred at hydraulic turbines, pumps, and pump-turbines. It also includes an analysis of some noise levels in power plants with Kaplan and Francis type turbines.

Specification Tolerance for Turbine Homology

Model tests of turbines are commonly used to determine the characteristics and particularly the expected efficiency of full size turbines. On some projects using propeller or kaplan type turbines, no accurate method of measuring the flow through the turbines is available. To assure that the full size turbine will perform in a homologuous manner with the model, tolerances for symmetry need to be established. Specifications are proposed for tolerance on the runner and on the fit of the wicket gates for large propeller type turbines.

Efficiency Calculation Formula of Kaplan Type Water Turbines by Their Model Experimented Efficiency

Efficiency Calculation Formula of Kaplan Type Water Turbines by Their Model Experimented Efficiency

Index Testing of Hydraulic Turbines

Abstract The object of this paper is (a) to bring to the attention of operating companies the benefits derived from index tests of hydraulic turbines, and especially those of the adjustable-blade propeller or Kaplan type; (b) to enumerate and discuss the presently known methods of determining relative discharge and hence relative efficiency; (c) to present an example of an index test of an adjustable-blade propeller turbine in sufficient detail to provide a guide for the conduct of such a test.

Safe Harbor Kaplan Turbines Design of Setting and Cavitation Limit as Developed at the Holtwood Hydraulic Laboratory

The Safe Harbor plant is the first large development in this country to use the Kaplan type of turbine. This paper describes the problems of design and operation which were comprehensively studied by means of model and field tests, with particular regard to the power limits of the turbines as established from a study of cavitation.

Safe Harbor Kaplan turbines

ONE of the numerous features of more than usual interest at the Safe Harbor hydroelectric development is the application of the Kaplan type of automatically adjustable blade propeller turbine. This type of turbine is used in all 6 units of the initial installation, each unit rated at 42,500 hp under a rated head of 55 ft. Safe Harbor is the first installation in America of Kaplan type turbines of large capacity, although they have been used for low head developments in Europe since 1919