2 research outputs found
Accelerated testing of tidal turbine main bearing in a full scale Nacelle Test Rig
Tidal Energy is one of the growing renewable energy technologies that is aimed at
tackling global energy challenges. The Horizontal Axis Tidal Turbine (HATT) is an
in-stream Tidal Energy Converter (TEC) which extracts kinetic energy from tidal
flows. These tidal turbines face many reliability challenges due to their complexity,
harsh operating environment and low accessibility. One of the component
contributing significantly to the reliability of a TEC is the bearing supporting the
rotating shaft within the nacelle. The reliability assessment of this component is
essential during the design process and before their eventual deployments. This
work is describes shaft bearing reliability assessment procedures.
In recent years, the Offshore Renewable Energy (ORE) Catapult’s National
Renewable Energy Centre has developed a dedicated multi axis test facility for full
scale testing of tidal turbine nacelles and components (i.e. Nautilus). This work
presents a methodology for testing tidal turbine shaft bearings in a representative
manner in the full scale nacelle test rig, Nautilus.
Two aspects are considered, namely the damage assessment and the damage
replication in an accelerated manner. The damage assessment process considers the
global loading on the shaft bearing and a Rigid Dynamics (RD) model has been
applied to identify the local bearing loads. Local loads are converted to stress
enabling the identification of stress-life relationship and bearing damage.
The damage replication process is aimed to evaluate the 20 year damage and the
Acceleration by Phase-shift (AbP) method has been developed to accelerate the
cumulative damage. The AbP method enables the assessment of performance
characteristics of shaft bearings in a laboratory environment, reducing failure rates,
validate performance in a cost effective manner by reduced testing times. Within
this work, novel processes for shaft bearing reliability assessments and
demonstration are suggested and it concludes with the presentation of a
recommended test plan for carrying out accelerated tests on a full scale bearin