development of a wave energy converter - owemes sea.pdf · development of a wave energy converter...

M. Bassetti, A. Corsini, G. Delibra, F. Rispoli, E. Tuccimei, P. Venturini

POSEIDONE projectUnder the auspicies of MATTM

Development of a wave energy converterfor Mediterranean operation

MARE X MED

FMGroup @ DMA-SapienzaCRAS Sapienza

G. Faggiolati, S. Piccinini, G. Romani, M. Ruggeri

F. Arena, P. Boccotti, S. Meduri, A. Romolo

FMGroup @ DMA-Sapienza

Outline

Motivations and aims

Description of the POSEIDONE project

Caisson concept and performance

Wells turbine design

REWEC-TW transient modeling and performance forecast

REWEC-TW test-rig & experimental validation campaigns

POSEIDONE Project

Source: based on Claesson, (1987)WEC 1996 estimate world wide

energy potential of 2.000

TWh/yr

comparable to 10% of the world energy demand on 2002

FMGroup @ DMA-Sapienza

Motivations (i), why Ocean Energy

wave energy features high specific

power

with the energy density in the range 20 to 70 kW/m for the best sea climates

more uniform day-time availability

when compared to the solar radiation peaks

POSEIDONE Project

ASME-ATI-UIT 2010

Sea state data. Hs e Tm annual distribution

Data:•Direction (Dir)•Wave height (Hs)•Wave period (Tm)

Source: APAT, www.idromare.it, 2005 data.

mHs 73.0=

sTm

18.4=

summer

period

FMGroup @ DMA-Sapienza

Motivations (i), why Ocean Energy

POSEIDONE Project

Motivations (ii), why Ocean Energy in Mediterranean sea

FMGroup @ DMA-Sapienza

Corsini A., et al Space-Time Mapping Of Wave Energy

Conversion Potential In Mediterranean Sea States. ASME-ATI-

UIT 2010

POSEIDONE Project

Motivations (iii), why Ocean Energy in Mediterranean sea

FMGroup @ DMA-Sapienza

Corsini A., et al Space-Time Mapping Of Wave Energy

Conversion Potential In Mediterranean Sea States. ASME-ATI-

UIT 2010

POSEIDONE Project

State-of-the-art class of wave energy converters

State-of-the-art Wells turbine, mono-plane

• self-rectifying turbine

• narrow operating margin

• designed for ocean conditions

above 30 kW/m

POSEIDONE Project

State-of-the-art OWC chamber

• standard OWC chamber features small period of oscillationdifficult resonance in case of near-shore waves

• reduced structural resistenceowing to the geometrical configuration

• opening in OWC attenuates energyconversion from small period waves

FMGroup @ DMA-Sapienza

New class of wave energy converters (i)

POSEIDONE Project

POSEIDONE project

This programme of research aims at the definition of a technology standard

for on-shore WEC suited for Mediterranean sea states and port breakwater

caisson integrationin a view to develop the first Italian full-scale prototype and a open-ocean test-rig @ NOEL Lab in Reggio Calabria

The proposed WEC defines a RES for µ-power generation (1 - 100 kWe)

The WEC is based on the combination

an innovative resonant caisson (U-OWC or REWEC3) designed by

P. Boccotti and industrialized by WavEnergy.it s.r.l. (pat. n.

1332519)

Wells turbine concept tailored to cope with low-energy wave

conditions

Boccotti P., 2007. Part I: Theory. Ocean Engineering. vol. 34, pp. 806-819.

Boccotti P., Filianoti P, Fiamma V, Arena F. 2007. Part II: A small-scale field experiment. Ocean Engineering. vol. 34, pp. 820-841.

New class of wave energy converters (ii), turbine

Design challenges for Mediterraneanapplications

• optimization of torque @ low flow rate

• stall resistent turbine

• compact unit at high rotational speed

• extension of duty time

POSEIDONE Project

experiments

Setoguchi T. Santhakumar S. Takao M. Kim T.H. Kaneko K. 2003 “A modified

Wells turbine for wave energy conversion” Renewable Energy

New class of wave energy converters (iii), turbine

Design challenges for Mediterraneanapplications

• optimization of torque @ low flow rate

• stall resistent turbine

• compact unit at high rotational speed

• extension of duty time

POSEIDONE Project

Torque coefficient

Efficiency

3600 rpm

3000 rpm

New class of wave energy converters (iv), turbine

Design challenges for Mediterraneanapplications

• optimization of torque @ low flow rate

• stall resistent turbine

• compact unit at high rotational speed

• extension of duty time

POSEIDONE Project

NACA0015

NACA0020

Università Mediterranea RC, Wavenergy.it

REWEC (Resonant Wave Energy Converter), known also as U-OWC or J-OWC

(Oscillating Water Column with a U/J duct) is a caisson breakwater to protect a

port and to convert wave energy into electrical power.

example of REWEC breakwater

a vertical duct (1) that is connected both to the sea through an upper opening (2), and to an inner room (3) through a

lower opening (4). This inner room contains a water mass (3a) in its lower part and an air pocket (3b) in its upper part. An

air-duct (5), which connects the air pocket (3b) to the atmosphere, contains a Wells turbine (6). Waves produce a

pressure fluctuation at the outer opening (2), water oscillates up and down in the duct (1), and the air pocket alternately is

compressed and expanded. Then, an alternate air flow is obtained in the air duct, which drives the turbine (6).

REsonant Wave Energy Converter

POSEIDONE Project

REsonant Wave Energy Converter

POSEIDONE Project

Main featuresThe plant is able to convert up to the 100% of the energy of swells (low

frequency waves) into the energy of a water column, then to wire (P. Boccotti)

The propagation speed of the wave energy reflected by an U-OWC can

approach zero.

Validation carried out @ NOEL (Natural Ocean Engineering Laboratory –

www.noel.unirc.it) 16 m long U-OWC was built on 2 m water depth “Ocean

Engineering” (Vol. 34 , Issues 5-6, 2007)

Main innovationssuper-amplification of swells is not dangerous for the stability of the caisson:

wind waves of severe sea storms remain, by far, more critical for the stability;

an U-OWC reduces the height of reflected wind waves, being able to absorb a

great share of the energy of wind waves (even if not the 100% in this case);

U-OWC candidates itself as the power plants being able to produce electrical

power from a renewable source with the greatest continuity

Design data requirements

Blade profile: NACA 0015Configuration: Monoplane

Outer diameter: 0.5 m

Rotational frequency: 3000 to 36000 rpm

Bulk velocity (design): 9.1 m/s

FMGroup @ DIMA-Sapienza

Target peak turbine power 2 kW

DIMA-FP TW1.5 turbine

Aerodynamic design process

Solidity checkCaisson hydrodynamic interface

Torque & power

Self-starting

Hub design

CFD-aided IGV-OGV design

DIMA-FP TW1.5 turbine

POSEIDONE Project

FMGroup @ DMA-Sapienza

Sensitivity to solidity

Solidità palare (σ) 0.64/0.5

Numero di pale (z) 3/4/7/8/9

DIMA-FP TW1.5 turbine

POSEIDONE Project

FMGroup @ DMA-Sapienza

Sensitivity to solidity

Hub to tip ratio (÷) 0.75/0.5

DIMA-FP TW1.5 turbine

POSEIDONE Project

FMGroup @ DMA-Sapienza

Rotor configuration & performance

shub c z L (m) T (N m) Paer(W) Pmecc (W) ηηηη

BEM simulation

5.25

BEM simulation

2237.74

BEM simulation

1979.06

BEM simulation

0.7370.64 0.75 7 0.108

DIMA-FP TW1.5 turbine

POSEIDONE Project

FMGroup @ DMA-Sapienza

Self-starting

shub c z L (m) T (N m) Paer(W) Pmecc (W) ηηηη

BEM simulation

5.20

BEM simulation

2215.00

BEM simulation

1960.00

BEM simulation

0.80.64 0.75 7 0.117

DIMA-FP TW1.5 turbine, CFD based design of IGV-OGV

POSEIDONE Project

FMGroup @ DMA-Sapienza

500000 nodes – 2700000 cells

Average aspect ratio 1.23

Max aspect ratio 15

Min aspect ratio 1

Wall distance 2.4×10-3

Inflow velocity radial profile

DIMA-FP TW1.5 turbine, CFD based design of IGV-OGV

POSEIDONE Project

FMGroup @ DMA-Sapienza

DIMA-FP TW1.5 turbine

CFD based design of IGV-OGV

POSEIDONE Project

FMGroup @ DMA-Sapienza A. Corsini, OWEMES2012, Rome, Italy, Sept 2012

DIMA-FP TW1.5 turbine

CFD based design of IGV-OGV performance

POSEIDONE Project

FMGroup @ DMA-Sapienza

DIMAFP-TW1.5CFD rotor only

DIMAFP-TW1.5design

DIMAFP-TW1.5field data

(NOEL Lab)

Q [m3/s] 1.0178 0.948

∆∆∆∆p [Pa] 2679 2578 2707

Cm [Nm] 4.48 5.07

P [W] 1408 1592 1401

DIMA-FP TW1.5 turbine

CFD based design of IGV-OGV performance

POSEIDONE Project

FMGroup @ DMA-Sapienza

-8000

-6000

-4000

-2000

0

2000

4000

6000

8000

10000

0,000 50,000 100,000 150,000 200,000 250,000 300,000 350,000

Pressure in the REWEC chamber (Pa)

DIMA-FP TW1.5 turbine

Transient performance simulation

POSEIDONE Project

FMGroup @ DMA-Sapienza

Data measured @ NOEL Reggio Calabria – typical winter sea state, Arena et al. (2011)

The wave power behaviour analysis was performed in a time-dependent fashion

TRNSYS 15 with IISiBat3 software

DIMA-FP TW1.5 turbine

Transient performance simulation

POSEIDONE Project

FMGroup @ DMA-Sapienza

-0,002

0

0,002

0,004

0,006

0,008

0,01

0 0,05 0,1 0,15 0,2

DIMA-FP TW pressure-power curve

(Corsini. Rispoli and Pesci, OWEMES 2006)

Transient modelling of WEC

Waveclimate

REWECchamber

Wellsturbine

Hs. Tm. h → Pw

POWC

Electric

load data

Control

system

PD

Aux gen-set

RES power system

Conventional power system

Electric grid

POSEIDONE Project

FMGroup @ DMA-Sapienza

0,0000

0,5000

1,0000

1,5000

2,0000

2,5000120,000 130,000 140,000 150,000 160,000 170,000 180,000

time (s)

(kW)

DIMA-FP TW1.5 turbine

Transient performance simulation

-0,5000

0,0000

0,5000

1,0000

1,5000

2,0000

2,5000

0 20 40 60 80 100

p (

kW

)

% time

POSEIDONE Project

FMGroup @ DMA-Sapienza

DIMA-FP TW1.5 turbine

Transient performance simulation

Il test rig Poseidone

anemometro e manometro

ventilatore

centrifugo

inverter e chopper di frenatura

raddrizzatore

Le curve caratteristiche

guide vanes

Le misure acustiche

Sono state condotte misure a regime stazionario in mandata per il rotore isolato

regime di rotazione: n = 2500 rpm

4 portate: Q1 = 1000 Nm3/h, Q2 = 2000 Nm3/h, Q3 = 3000 Nm3/h, Q4 = 4000 Nm3/h (stallo)

4 posizioni per il microfono: A, B, C, D

setup misure acustiche

Confronto dei livelli di pressione sonora al variare della portata

I livelli di pressione sonora crescono con la portata a tutte le frequenze

POSEIDONE consortium

An integrated procedure for the design of a wave energy converter developed for Mediterranean operation

FMGroup @ DMA-SapienzaCRAS Sapienza