In the nuclear power sector, electricity is generated from the steam generated by large turbines which are highly reliant on efficient electro-hydraulic turbine speed control systems (EHC). These systems offer a wide range of control options and operate at pressures of over 1000 psi to ensure rapid hydraulic response. At these pressures the potential for leaks of hydraulic fluid is greater as i...

CFD (Computational Fluid Dynamic) is today standard procedure for simulating and analysing fluid flow through hydraulic machines. This is a process where fluid flow domain is divided into many small volumes where governing equations are converted into algebraic equations, which can be solved numerically. Computational result strongly depends on methods used for converting governing to algebraic...

The hump feature is one of the major instabilities in pump-turbines. When pump-turbines operate in the hump region, strong noise and serious fluctuations can be observed, which are harmful to their safe and stable operation and can even destroy the whole unit as well as water conveyance system. In this paper, a low specific speed (nq = 36.1 min−1) pump-turbine model was experimentally investiga...

The hump characteristic is one of the major instabilities in pump-turbines. When pumpturbines operate in the hump region, strong noise and serious fluctuations could be observed, which are harmful to the safe and stable operations and even destroy the whole unit as well as water conveyance system. In this paper, a low specific speed (nq = 36.1 min−1) pump-turbine model was experimentally invest...

Gas turbine cooling systems have the branched networks of various channels whose hydraulic and heat exchange capabilities define air flow required for parts and, thus, directly influence efficiency gas turbines. Cooling system elements are, in particular, throttles, diaphragms, seals, openings that act as regulating or to maintain pressure system. As a rule, this type significant drop, therefor...

Hydropower has grown to play an important role in power systems including increasing clean and low-carbon energies, the effect of electric loads should be basically evaluated for reliable operation these systems. For hydraulic–mechanical–electrical system hydropower station, state equation model stability evaluation was derived with typical load models elastic pipe flow, after experimental conf...

The incorporation of computational fluid dynamics in the design of modern hydraulic turbines appears to be necessary in order to improve their efficiency and cost-effectiveness beyond the traditional design practices. A numerical optimization methodology is developed and applied in the present work to a Turgo water turbine. The fluid is simulated by a Lagrangian mesh-free approach that can prov...

A three-magnet array unilateral NMR sensor with a homogeneous sensitive spot was employed for assessing aging of the turbine oils used in two different power stations. The Carr-Purcell-Meiboom-Gill (CPMG) sequence and Inversion Recovery-prepared CPMG were employed for measuring the ¹H-NMR transverse and longitudinal relaxation times of turbine oils with different service status. Two signal comp...