Impact of startup scheme on Francis runner life expectancy

Gagnon, Martin; Tahan, Antoine; Bocher, Philippe; Thibault, Denis

doi:10.1088/1755-1315/12/1/012107

Cited by 53 publications

(33 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In order to do this, Hydro-Québec decided to use the data from their measurement campaigns on Francis and propeller runners to identify and validate dynamic models that will represent the turbines behavior and enable start-up optimization. This paper follows previous work conducted at Hydro-Quebec by Gagnon et al [1][2][3], and by other researchers [4,5], on the impact of a transient operation on Francis runners, and builds on the review on fatigue damage mechanisms in hydro turbines [6].…”

Section: Introductionmentioning

confidence: 75%

Modeling the dynamic behavior of turbine runner blades during transients using indirect measurements

Diagne

Gagnon

Tahan

2016

IOP Conf. Ser.: Earth Environ. Sci.

Self Cite

View full text Add to dashboard Cite

Abstract. Turbine start-up transients are induced by the wicket gates opening sequence and generate high amplitude stress cycles. These stress cycles have a detrimental effect leading to faster crack growth in the runner blades. Using a series of direct measurements taken on a prototype runner in order to find the optimal start-up parameters exposes both the runner and the instrumentation to a series of successive damaging transient events during the optimization process. To solve this, finding sensors strongly correlated to strain gauges and whose signals can be easily obtained to identify a model to predict the strain, instead of directly measuring it, would reduce the risk, cost and downtime associated with a measurement campaign. This paper shows that turbine shaft torsion measurements is highly correlated to the strain at a runner blade hotspot, and we demonstrate that the ARMAX model can be used to represent the dynamic system in order to minimize the strain on blades.

show abstract

Section: Introductionmentioning

confidence: 75%

Modeling the dynamic behavior of turbine runner blades during transients using indirect measurements

Diagne

Gagnon

Tahan

2016

IOP Conf. Ser.: Earth Environ. Sci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, operating at no-load (with just enough flow to overcome machine losses) wastes valuable water resources, while operation at low load, particularly within the so-called rough running zone, is associated with excessive machine vibration and decreased asset life and therefore should be avoided whenever possible [2][3][4].…”

Section: Introductionmentioning

confidence: 99%

Rapid Reserve Generation from a Francis Turbine for System Frequency Control

et al. 2017

View full text Add to dashboard Cite

Abstract:The increase in contributions from non base load renewables, such as wind and solar, can have adverse effects on the stability of an electrical grid. In this study, the possibility of rapidly loading a Francis turbine from a tail water depression (TWD) mode for providing additional system frequency control is investigated. Based on the analysis of full-scale TWD test results and key findings from the transient testing of a micro-hydro scale turbine unit, a detailed description of the TWD transition process is given. The formulation of an improved turbine model for use in one-dimensional hydro-electric plant models is presented with simulation results compared to full-scale data. The analytical model, which calculates output power according to the conservation of angular momentum and identified sources of loss, is used in parallel with full-scale and model scale test observations to elucidate the events and mechanisms occurring during this proposed transition. The output response, in terms of active power, was found to be highly dependent on guide vane opening rate in both full-scale and model tests. For an approximate doubling in opening rate, the duration of the reverse power flow was reduced by 38% and 21%, for full-scale and model units, while the low pressure transient increased by 16% and 8%, respectively. The analytical model was shown to capture the general response characteristic in all cases tested; however, output power response was over predicted due to two identified model assumptions made, while, for the more rapid opening, the penstock pressure was under predicted by approximately 15%.

show abstract

“…Hence, transient events often account for most of the damages sustained by hydroelectric turbines during their operation [2]. They affect the turbine lifetime both by accelerating crack propagation on the runner blades [3] and damaging the bearings. The exerted unsteady fluctuations during the transients are a challenge for the turbine designers and power plant owners because they are difficult to predict during the design stage.…”

Section: Introductionmentioning

confidence: 99%

“…The study showed that in both cases the fatigue damage increases during load variation. Gagnon et al [3] showed that the damage to a Francis runner during start-up event is significantly dependent on the start-up scheme. Houde et al, [1] directly measured the pressure fluctuations exerted on the runner blades of a propeller turbine during runaway and speed-no-load conditions.…”

Section: Introductionmentioning

confidence: 99%

Effects of load variation on a Kaplan turbine runner

Amiri¹,

Mulu

Cervantes

et al. 2016

International Journal of Fluid Machinery and Systems

View full text Add to dashboard Cite

Introduction of intermittent electricity production systems like wind and solar power to electricity market together with the deregulation of electricity markets resulted in numerous start/stops, load variations and off-design operation of water turbines. Hydraulic turbines suffer from the varying loads exerted on their stationary and rotating parts during load variations since they are not designed for such operating conditions. Investigations on part load operation of single regulated turbines, i.e., Francis and propeller, proved the formation of a rotating vortex rope (RVR) in the draft tube. The RVR induces pressure pulsations in the axial and rotating directions called plunging and rotating modes, respectively. This results in oscillating forces with two different frequencies on the runner blades, bearings and other rotating parts of the turbine. This study investigates the effect of transient operations on the pressure fluctuations exerted on the runner and mechanism of the RVR formation/mitigation. Draft tube and runner blades of the Porjus U9 model, a Kaplan turbine, were equipped with pressure sensors for this purpose. The model was run in off-cam mode during different load variations. The results showed that the transients between the best efficiency point and the high load occurs in a smooth way. However, during transitions to the part load a RVR forms in the draft tube which induces high level of fluctuations with two frequencies on the runner; plunging and rotating mode. Formation of the RVR during the load rejections coincides with sudden pressure change on the runner while its mitigation occurs in a smooth way.

show abstract

Impact of startup scheme on Francis runner life expectancy

Cited by 53 publications

References 1 publication

Modeling the dynamic behavior of turbine runner blades during transients using indirect measurements

Modeling the dynamic behavior of turbine runner blades during transients using indirect measurements

Rapid Reserve Generation from a Francis Turbine for System Frequency Control

Effects of load variation on a Kaplan turbine runner

Contact Info

Product

Resources

About