A Ddaskalakis AquacultureEngineering Technology Oct 19 17+10

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Paper presented in Aquaculture Europe 2011

Paper presented in Aquaculture Europe 2011

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  • 1. AQUACULTURE EUROPE 2011 OPEN SEA FISH FARMS BASED ON INTEGRATED INTENSE FLOATATION AND WAVE ABSORBING TECHNOLOGIES OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr Presented by : Dr Antonis Daskalakis Offshore Energy Systems SA
  • 2. AQUACULTURE EUROPE 2011 WHY DEEP WATERS OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr Presented by : Dr Antonis Daskalakis
    • Moving to deep waters and far from the coasts is inevitable due to:
    • Increased pressures from local communities
    • Contradiction with other social and economical activities
    • Increased concerns on health and environmental issues
    • However it is for the benefits of the industry itself to seek ways of doing so.
    • The limited space for development, leading to small size units and a disperse activity.
    • The confined self cleaning capability of protected waters.
    • Fish health problems and decease spreading, affect productivity and product quality .
    • Fish growing speed and fish taste which improve considerably in deep waters
  • 3. AQUACULTURE EUROPE 2011 WHY DEEP WATERS OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr
    • Costs involved in going into deep waters will be compensated by:
    • Concentrating production into a small but of considerable size units increasing capacity, reducing production and logistic costs.
    • Improving the quality of the product and widening the market horizons.
    • Cultivating new fish species, increasing product variability and market penetration.
    INTEGRATED TECHNOLOGIES HAVE TO BE DEVELOPED Presented by : Dr Antonis Daskalakis
  • 4. AQUACULTURE EUROPE 2011 THE MOVE TO DEEP WATERS IS ALREADY A REALITY OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr Presented by : Dr Antonis Daskalakis
    • Extensive research and investment efforts are undertaken worldwide. More than $100 million have been spent in USA over a decade.
    • USA, China, Chile, Israel are reported to lead the efforts.
    • Main focus is put on sank cages in order to avoid the effects of the sea waves.
    • The blue revolution in Hawaii, the subflex in Israel, the “ i 0 cagesi+ ” , are such installations.
    • However ,
    • A new production process is necessary and special skills have to be developed in order to realize this type of production.
    We believe that staying at surface presents a challenge which has to be answered, for many reasons.
  • 5. AQUACULTURE EUROPE 2011 WHAT IS INTENSE FLOATATION TECHNOLOGY OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr
    • BODY UNDER INTENSE FLOATATION: BASIC MORPHOLOGY
    • The main buoyant unit (MBU) that produces buoyancy in excess of the body total weight.
    • The columns that support and connect the deck with the MBU providing variable buoyancy.
    • The deck structure that provides space and undertakes the live loads.
    • The anchor lines that connect the body with the sea bed being always under tension.
    • The anchor blocks which can undertake the tension from the lines and providing horizontal holding power.
    Presented by : Dr Antonis Daskalakis
  • 6. AQUACULTURE EUROPE 2011 WHAT IS INTENSE FLOATATION TECHNOLOGY OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr
    • A BODY UNDER IF IS SUBJECTED TO WEATHER FORCES ,LIKE ANY OTHER BODY AT SEA
    • However the following make it to present a peculiar behavior:
    • The MBU is below the water to reduce wave forces and for a safe operation.
    • The body presents a small water plane area reducing wave forces.
    • The fairleads are forced to move on circular trajectories.
    • Only planar motions are present with only a small heave movement. In fact the body moves on the plane parallel to itself with its deck always horizontal .
    • The line lengths are kept short compared to catenary mooring lines.
    Presented by : Dr Antonis Daskalakis
  • 7. AQUACULTURE EUROPE 2011 MATHEMATICAL MODELLING OF AN INTENSE FLOATATION BODY OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr The mathematical formulation follows the same lines as for a free floating body based on Newton’s second law: The total forces exerted on the body (in the three directions) are: F m : Forces from the mooring lines F w : Weather forces (wind, waves, currents) and F w = F h + F l (high and low frequency excitations) F o : Live or operational forces (loads) Presented by : Dr Antonis Daskalakis surge sway yaw THE PECULIARITIES OF AN IFB PROVIDE USEFUL CHARACTERISTICS. HOWEVER INTENSE STUDY BEFORE BUILDING AN INTENSE FLOATATION TECHNOLOGY .
  • 8. AQUACULTURE EUROPE 2011 MATHEMATICAL MODELLING OF AN INTENSE FLOATATION BODY OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr
    • IMPORTANT NOTES
    • The importance of separating the mathematical model into low and high frequency.
    • This is because natural frequencies of an IFB can be within the band of low frequency excitations like swells.
    • The body as it is described here operates like an inverted pendulum and its natural frequency is given by:
    • Under certain circumstances it is possible to tune the natural frequency to avoid excitations. This can be done during design but also during operation.
    P a : excess buoyancy M a : body mass + added mass L : line length Presented by : Dr Antonis Daskalakis
  • 9. AQUACULTURE EUROPE 2011 MATHEMATICAL MODELLING OF AN INTENSE FLOATATION BODY OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr RESULTS FROM THE SIMULATION PROGRAM IN HARMONIC WAVES OF AN INTENSE FLOTATION WIND MEASUREMENT PLATFORM Total wave force in KN Excursions of the platform (m) The variation of line tension and total Excess buoyancy An IF Wind Measurement Platform Presented by : Dr Antonis Daskalakis Input Values Wave Height (m) 8 Wave Period (sec) 6 Mean wind speed (m/sec) 36 Current speed (Knots) 1.5
  • 10. AQUACULTURE EUROPE 2011 CALCULATING PROCEDURES OF AN INTENSE FLOATATION BODY OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr BASED ON THE GENERAL MATHEMATICAL MODELING EACH COMPONENT NEEDS AN INDIVIDUAL STUDY ACCORDING TO ITS ROLE.
    • The body itself: Two main areas of interest:
    • The body motions,
    • Its strength for the design loads (environmental and operating).
    • Extreme conditions and special low frequency phenomena can be studied.
    • Wave forces are calculated based on Morison's equation.
    • For the strength calculations a finite element model developed in SAP-2000. is developed.
    • Mooring lines : Tensions under all circumstances are calculated from time domain simulation.
    • Anchors: Calculated minimum weight (for gravity anchors) and required holding capacity.
    Presented by : Dr Antonis Daskalakis
  • 11. AQUACULTURE EUROPE 2011 TECHNOLOGIES TO EXPLOIT INTENSE FLOATATION BODIES OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr BODY DESIGN AND REALISATION
    • Simple structures are developed for minimum forces, easy installation and minimum maintenance.
    • To lower costs and increase flexibility, the main buoyancy module is split into two major parts :
      • Permanent buoyant volume
      • Water tanks for ballasting and de-ballasting
    • Modular structures are developed which can be connected together to form the required area and capacity.
    • Vertical floaters can be either the strength members of the body or just buoyant units.
    • Special connectors are developed (screw, wedge type connectors, elasto-dynamic bearing type connector
    Presented by : Dr Antonis Daskalakis
  • 12. AQUACULTURE EUROPE 2011 TECHNOLOGIES TO EXPLOIT INTENSE FLOATATION BODIES OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr MOORING LINE DESIGN AND REALISATION
    • The mooring lines can be of wire rope (or even synthetic rope of high strength).
    • Each line is composed by a number of individual lines (block of lines) so that :
      • the required loads can be undertaken, under all conditions,
      • redundancy can be provided,
      • while a line can be replaced in situ.
    • Special universal connectors are developed that provide :
      • Movements in all directions
      • Easy fitting of a number of individual lines to form a complete block of an anchor line.
      • Easy handling and securing
    Presented by : Dr Antonis Daskalakis
  • 13. AQUACULTURE EUROPE 2011 TECHNOLOGIES TO EXPLOIT INTENSE FLOATATION BODIES OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr ANCHORS DESIGN AND REALISATION
    • The anchors are a major component of the system.
    • Undertake the excess buoyancy and provide holding capacity.
    • We introduce here the concept of the split anchor .
      • The first part, a block is preinstalled at the sea bottom .
      • The body itself carries the second part, anchors which during transportation and installation function as ballast weights.
      • During installation the anchors are lowered to specially designed sockets on the preinstalled block.
      • The preinstalled block provides precision and ease of installation .
    • Knowledge comes the oil industry in designing and constructing effective anchors.
    Presented by : Dr Antonis Daskalakis
  • 14. AQUACULTURE EUROPE 2011 APPLICATIONS OF THE IN INTENSE FLOATATION TECHNOLOGIES OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr FISHING CAGES Fishing cages for deep and very deep waters are designed as intense floatation bodies.: In several shapes and sizes depending on the requirements. In heights according to prevailing wave climate. With deck height depending on the platform envisaged use. It can be workable at any conditions or it can be allowed to be washable above certain conditions.
    • Net design is of particular importance.
    • Instead of the freely moving net following the current forces we propose the double net arrangement.
    • The first is external and more or less permanently attached to the mooring lines or to additional auxiliary vertical lines. It is open at the top and at the bottom as well extends as deeply as it is required.
    • The second is the fish net, which is kept inside the the external net. It can be a normal or a sinkable one.
    Presented by : Dr Antonis Daskalakis
  • 15. AQUACULTURE EUROPE 2011 APPLICATIONS OF THE IN INTENSE FLOATATION TECHNOLOGIES OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr FISHING CAGES
    • Fishing cages are of modular structure and they can be connected with several ways to form a complete unit:
    • The hexagon shape provided here is only one of the possible formulations>
    • The cages can be organized in subunits according to the production needs.
    • Supporting structures, like working platforms, can also be arranged accordingly.
    Presented by : Dr Antonis Daskalakis
  • 16. AQUACULTURE EUROPE 2011 APPLICATIONS OF THE IN INTENSE FLOATATION TECHNOLOGIES OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr WORKING PLATFORMS
    • Working platforms can be designed and constructed as IFB to serve all the needs of a complete installation.
    • Working platforms are of modular construction and they can be connected together to form the shape, the required load area, the necessary payload.
    • Working platforms can carry :
    • Silos and feeding apparatus
    • Offices and working spaces
    • Warehouses and machinery spaces
    • Accommodation facilities
    • Crew recreational installations
    Presented by : Dr Antonis Daskalakis A two storey accommodation facility An open door personnel recreational platform
  • 17. AQUACULTURE EUROPE 2011 APPLICATIONS OF THE IN INTENSE FLOATATION TECHNOLOGIES OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr LIGHTING AND SURVEILANCE TOWERS
    • Lighting towers are IFB designed to carry a lattice type tower of adequate height.
    • Photovoltaic panels can gather enough energy to feed the lights installed at the top of the tower, while a battery set can store energy for the night hours .
    • A small generator which automatically turns on when the battery charge goes down can secure complete energy autonomy.
    • A small enclosed area can be provided for a night guard with substantial facilities.
    • Wireless Cameras (also thermal) can provide an all day and night surveillance.
    • A megaphone system can be used for direct communication of the office with the plant.
    • The tower can be installed from 30 m and up to deep and very deep waters.
    Presented by : Dr Antonis Daskalakis
  • 18. AQUACULTURE EUROPE 2011 WAVE ABSORBING TECHNOLOGIES OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr
    • The idea comes from the fact that wave energyis concentrated at and near the sea surface.
    • In contrast gravity structures are build on a reverse order of mass distribution.
    • We need something to interact with waves in the actual area of energy concentration.
    WHY WAVE ABSORBERS
    • The first idea leads to floating structures. But free floating structures move with the waves and produce waves.
    • Existing breakwaters have a limited capacity up to 3-3.5 sec of wave periods.
    • We replace the free floating body with an IFB. Howver,
    • Wave breakers act as an obstacle to the waves, creating huge forces.
    • Instead of a perpendicular wall to waves we fill the empty space with wave absorbing cells.
    Presented by : Dr Antonis Daskalakis
  • 19. AQUACULTURE EUROPE 2011 WAVE ABSORBING TECHNOLOGIES OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr
    • There are several proposals for absorbing apparatus like the perforated plates. With the aim:
    • To increase absorbing capacity, to minimize forces, to design something that can be produced under factory conditions,
    WAVE ABSORBING CELLS
    • We have developed the cell type wave absorbers shown here
    • The cells are of variable inclination in order to break the wave field into a number of counteracting wave fields.
    • The cells are standardized in sizes and they can be installed to fill the complete space between floaters and deck.
    • Wave absorbers can be used to create ports, to protect coasts from erosion, to protect open water installations like aquaculture.
    • The IFB, carrying the absorbing cells, consists a wave absorber module.
    • Modules are connected together to form the complete wave absorber.
    Presented by : Dr Antonis Daskalakis
  • 20. AQUACULTURE EUROPE 2011 WAVE ABSORBING TECHNOLOGIES OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr The wave field of an incoming wave can be expressed as follows: In the absorbing cells the field is “broken” to a number of fields Φ i , and diffracted waves Φ d. The outgoing wave field Φ D with less energy content. The forces exerted on the cell surface are of reduced order. THEORETICAL ASPECTS OF WAVE ABSORBING CELLS Field tests of wave absorbers, and of a WAVE ENERGY EXPLOITATION (WECO) apparatus have been contacted in the area of Laurion. The results have led to a complete range of products. A first application is already working in the port of Laurion. Presented by : Dr Antonis Daskalakis
  • 21. AQUACULTURE EUROPE 2011 WAVE ABSORBING TECHNOLOGIES OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr
    • Floating wave absorbers of intense floatation
    • for deep and very deep waters
    • Bottom supported wave absorbers of a piled
    • structure for shallow waters
    • Absorbing docks for internal port dock
    • constructions
    PRODUCT RANGE A complete range of wave absorbing products has been developed including: Presented by : Dr Antonis Daskalakis
  • 22. AQUACULTURE EUROPE 2011 OUR VISION FOR THE NEW ERA IN AQUACULTURE OFFSHORE ENERGY SYSTEMS SA Address: 48 Karaoli & Dimitriou str., GR-152 32 Halandri, Greece Tel . +30 210 6775 003, Fax +30 210 6812 770, www.martech.gr , email : tech @ martech . gr Presented by : Dr Antonis Daskalakis