9/10/2014 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME 1
IMO/MEPC assigned to the 27 th ITTC the task of revising ISO 15016:2002 to incorporate assessment of EEDI of a new building. IMO asked for a transparent, un-ambiguous and practical method acceptable for all stakeholders as well as for the assessment of the IMO EEDI. ITTC formed the ad hoc Specialist Committee on the Performance of Ships at Sea (PSS) and assigned to it the task to devise new procedure for: 27 th ITTC PSS Committee produced two procedures for Speed and Power Trials: , Part I Preparation and Conduct Part II Analysis of Speed/Power Trial Data 9/10/2014 2 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
63 rd IMO/MEPC adopted four sets of Guidelines to support the implementation of the mandatory Regulations on Energy Efficiency for Ships in MARPOL Annex VI, entered into force on 1 January 2013: On the calculation method of attained Energy 1. Efficiency Design Index (EEDI) for new ships (2002); 2. On the development of a Ship Energy Efficiency Management Plan (SEEMP) (2012); On on survey and certification of the Energy Efficiency 3. Design Index (EEDI) (2012); and 4. On the calculation of reference lines for use with the Energy Efficiency Design Index (EEDI). 9/10/2014 3 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
EEDI = CFME*(SFC ME *P ME +SFC AE *P AE )/(Capacity*V REF ) Where: CFME - Carbon emission factor SFC ME - Specific fuel consumption of main engine SFC AE - Specific fuel consumption of auxiliary engines P ME - 75% of rated installed power (MCR) for each ME w/o any deduction for shaft generators P AE - Installed auxiliary power Capacity – For dry cargo carriers, tankers, gas tankers, containerships, ro-ro cargo and general cargo ships, deadweight should be used instead (tons). V REF – Ship speed (kn) in deep water for max design load condition ( capacity ) as defined above, at the main engine shaft power at 75%MCR, assuming calm weather (no wind & no waves). 9/10/2014 4 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
EEDI(details) the main engine power reduction due to installed power for each required auxiliary waste heat recovery innovative energy main engine (j) engine power system efficient technology neff neff M nME M nPTI f C SFC P P C SFC f P f P C SFC f P C SFC j FME ( i ) ME ( i ) ME ( i ) AE FAE AE j PTI ( i ) eff ( i ) AEeff ( i ) FAE AE eff ( i ) eff ( i ) FME ME j 1 i 1 j 1 i 1 i 1 i 1 EEDI f Capacity V f i ref w f W is a non-dimensional coefficient Capacity: indicating the decrease of speed in For cargo carriers, tankers, gas tankers, representative sea conditions of wave container ships, ro-ro cargo and height, wave frequency and wind speed passenger ships and general cargo ships, Vref (ship speed) (e.g., Beaufort Scale 6), > deadweight measured in nautical miles per hour (knot), • For passenger ships, on deep water in the maximum design load >gross tonnage ( fw =1 at this moment) condition (Capacity) at the output of the engine(s) and assuming the weather is calm with no wind and no waves. 9/10/2014 5 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
Reduction of EEDI EEDI Application Ship types for EEDI After 1st After 1st calculation* January September 2013 2015 All new ships (according below table) of 400GT and above, build from 1st Bulk carrier X January 2013 Gas carrier X ** * not apply to ships of diesel-electric Tanker X propulsion, turbine propulsion Container ship X and hybrid propulsion system Reefer X ** separate to Gas carrier and LNG Combination carrier X carrier Passenger ship X*** *** only regulated for Passenger ship having non-conventional RO-RO cargo ship X propulsion RO-RO passenger ship X 6 9/10/2014 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
IMO Stipulated EEDI Reduction Rate Phase Vessel EEDI # built below base line Phase 0 Jan 2013 – 0% Dec 2014 Phase 1 Jan 2015 – 10% Dec 2019 Phase 2 Jan 2020 – 20% Dec 2024 Phase 3 Jan 2025 – > 30% 9/10/2014 7 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
EEDI Survey and Certification 9/10/2014 8 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
Practical Aspects of EEDI Prediction 9/10/2014 9 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
POWER CURVES 9/10/2014 10 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
POWER CURVES ESTIMATION 9/10/2014 11 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
Conclusions on EEDI Verification Process EEDI prediction process shall follow the Industry guidelines Model tests shall be conducted according to ITTC Recommended Procedures In EEDI regulation, model basins are requested to build a quality control system, such as ISO-9000 or equivalent Trials are carried out at ballast condition while EEDI refers to the full load (design) condition. Extrapolation is carried out using the same thrust identity or correlation coefficient method of 1978 ITTC. Studies showed that C P and δΔC FC vary significantly with displacement. Further studies on δC P /δΔC FC are necessary. 9/10/2014 12 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
Preparation and Conduct Purpose: To determine ship performance in terms of speed, power and propeller revolutions under prescribed ship conditions, and subsequently: Verify the satisfactory attainment of the contractually stipulated Ship Speed Provide the Ship Speed for the calculation of the Energy Efficiency Design Index (EEDI) as required by IMO. To derive the speed/power performance of the vessel from the measured speed over ground, shaft torque and rpm, the Direct Power Method is recommended . 9/10/2014 13 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
Preparation and Conduct Part I is to define and specify: Responsibility of each party involved, Trial preparations, Vessel and propeller conditions, Limiting weather (wind) and sea conditions, Trial procedure, Execution of the trial, Measurements required, Data acquisition and recording Processing of the results. 9/10/2014 14 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
Trial Preparations Hull surface roughness and fouling – Clean & smooth hull Propeller roughness and fouling – clean & smooth (polished) propeller Draughts - averaging the ship draft mark readings => by draft marks and/or draft gauging system Trim < 1.0% Tm; Optimum trim do not considered (varies with speed) Displacement - within +/-2% difference from the actual required displacement 9/10/2014 15 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
Wind and Wave Measurements Relative Wind – Speed and direction • Correction for superstructure • Correction for height > 10 m above sea level Waves – Hs/Tp and direction • Visual observation (min 3 observers) • Wave buoy • Wave radar Current – speed and direction • ”Mean -of- means” of vessel speed during two consecutive double runscurrent speed varies parabolically over time • ‘’Iterative method” ( assumes to vary with a semidiurnal period P(Vs)=a+bVs^q 9/10/2014 16 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
Wind/ Wave Limits Limiting weather (wind) and sea conditions : Wind speed should not be higher than: Beaufort number 6, for vessels with L >100 m Beaufort number 5, for vessel with ≤100 m 9/10/2014 17 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
Preparation and Conduct Ship track during double run: These runs comprise: Two (2) Double runs (at the same power setting) around the Contract Power, Two (2) Double runs (at the same power setting) around EEDI Power (i.e. 75% MCR), Two (2) Double Runs for at least one other power setting between 65% and 100% MCR. Logging duration minimum 10 min for all runs 9/10/2014 18 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
Preparation and Conduct Data Acquisition and Recording: Time Propeller shaft torque Propeller shaft rpm Pitch of CPP Ship positional data Ship heading Ship’s speed over ground Relative wind direction Relative wind speed Wave height, period and direction 9/10/2014 19 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
Analysis Main Objectives of Part II: To define procedure for the evaluation and correction of speed/power trials covering: Wind correction Waves correction Current correction Temperature and salinity correction Shallow water effect correction Displacement correction 9/10/2014 20 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
Analysis 9/10/2014 21 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
Analysis Direct power method is applied, combined with test results from load variation tests. with P SC : corrected power, P SM : measured power, V S : ship speed through the water, Δ P : required correction for power, Δ R : resistance increase, η D : propulsion efficiency coefficient. 9/10/2014 22 TECHNICAL MEETING OF THE GREEK SECTION OF SNAME
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