The Delft Offshore Wind Turbine Concept (DOT)

Transcription

1 December 2009 The Delft Offshore Wind Turbine Concept (DOT) A hydraulic solution for offshore wind energy Antonio Jarquín Laguna Delft University of Technology Challenge the future

2 Table of Contents Current turbine technology Delft Offshore Turbines Hydraulic energy transfer Overview DOT project Preliminary results Conclusions The Delft Offshore Wind Turbine Concept (DOT) 2 16

3 Current Turbine Technology General Danish concept (3 blades) Heavy nacelle Huge gearbox + big generator Huge amounts of switch gear Many components many failures high maintenance Offshore Difficult installation Difficult maintenance Not yet cost effective without government subsidies The Delft Offshore Wind Turbine Concept (DOT) 3 16

4 Delft Offshore Turbines (DOT) TU Delft: step away from incremental improvements Design turbines specifically for offshore Two main drivers: Size Cost of energy So, let us start by? The Delft Offshore Wind Turbine Concept (DOT) 4 16

5 Delft Offshore Turbines (DOT) Everything out of the nacelle! So, we only have: rotating kinetic energy a point to deliver electrons? Everything in between is for us to design The Delft Offshore Wind Turbine Concept (DOT) 5 16

6 Delft Offshore Turbines (DOT) Power Transmission Current systems: High top-mass High cost of components Dynamic loads High maintenance Solution? use hydraulic power transmission: we pump! The Delft Offshore Wind Turbine Concept (DOT) 6 16

7 Hydraulic energy transfer Hydraulic Wind Turbines Advantages Gearless transmission More robust than mechanical gearboxes High power-to-weight ratio Damping of dynamic loads High reliability/low maintenance Challenges High efficiency Seawater as hydraulic fluid Wide operational range (!) Vital components not available (Scaling effects) The Delft Offshore Wind Turbine Concept (DOT) 7 16

8 Overview DOT Fixed displacement pump Fixed displacement motor Variable displacement pump -No need of control without significant loss of efficiency - η vol can be improved (internal seals and scaling effects) -No need of control, high efficiency -Control to get high performance with high pressures and low flows -Constant pressure to allow connection with other turbines -Reduced friction losses Seawater line The Delft Offshore Wind Turbine Concept (DOT) 8 16

9 Centralized electricity generation Electricity to shore Hydro Plant The Delft Offshore Wind Turbine Concept (DOT) 9 16

10 Centralized electricity generation Hydraulic turbines Hydro- power plants have the highest operating efficiency of all known generation systems No need of dam or large reservoir Large capacities up to 400 MW per unit High efficiency at partial loads (>90 %) Onshore operation and control Largely automated (operating costs are relatively low) High Voltage The Delft Offshore Wind Turbine Concept (DOT) 10 16

11 Hydraulic wind developments Current hydraulic wind developments (Hydraulic transmission) The Delft Offshore Wind Turbine Concept (DOT) 11 16

12 Preliminary Results For a single turbine 12 Powercurves Comparable power compared with a commercial turbine Limited by rotor loads Power [MW] P DOT single turbine P RePow er 5 MW Wind Speed U [m/s] No longer limited by Max torque of individual generators!! The Delft Offshore Wind Turbine Concept (DOT) 12 16

13 Preliminary Results For 20x turbines Connected in parallel 200 Powercurves Total P DOT P RePow er 5MW W20x Lower energy production for low wind speeds High potential for high wind speeds Power [MW] Wind Speed U [m/s] The Delft Offshore Wind Turbine Concept (DOT) 13 16

14 Preliminary Results Efficiencies Energy transfer performance Main limitation driven by the variable displacement pump performance η η generator η generator piping η generator piping closed loop 0.1 ηη piping closed varpump generator loop η η closed varpump Final generator pipingloop Wind Speed U [m/s] The Delft Offshore Wind Turbine Concept (DOT) 14 16

15 Conclusions Centralized electricity generation can be possible with hydraulics transmission High potential for high wind speeds Further analysis in dynamics and control Economical study needed Challenges Seawater as an hydraulic fluid (wear and corrosion) Availability of components A solution for large wind offshore The Delft Offshore Wind Turbine Concept (DOT) 15 16

16 Thank you!! Questions? es, we can! The Delft Offshore Wind Turbine Concept (DOT) 16 16

17 General configuration Pump 1 Rotor High pressure Low pressure p up to 350 bar M Motor 20x Seawater Pump bar Pelton turbine ~ Synch Generator The Delft Offshore Wind Turbine Concept (DOT) 17 16

18 Concept of the DOT energy transfer system Wind Energy (KE) Mechanical Energy Hydraulic Energy Electrical Energy Wind Speed Rotor T ω Hydraulic Pump p Q Generato r Platform Electrical power The Delft Offshore Wind Turbine Concept (DOT) 18 16

19 Variable displacement pump 1 Energy transfer performance Energy transfer performance 0.05 Dp nom 0.10 Dp nom 0.15 Dp nom η max Fix D p Var D p Dp nom Dp nom 0.15 Dp nom 0.75 η Dp nom 0.50 Dp nom Wind Speed U [m/s] 2 Volumetric displacement of the pump Dp nom Wind Speed U [m/s] D p [m 3 /rpm] Wind Speed U [m/s] The Delft Offshore Wind Turbine Concept (DOT) 19 16