EEDI formula

IMO EEDI Formula
 Concept

Actual CO 2 emission
EEDI=
Transport work

 Specific Formula

M nME M nPTI neff neff
*
fj PME (i ) CFME (i ) SFCME (i ) PAE CFAE SFC AE fj PPTI (i ) f eff (i ) PAEeff (i ) CFAE SFC AE f eff (i ) Peff (i ) CFME SFCME
j 1 i 1 j 1 i 1 i 1 i 1

fi Capacity Vref f w

IMO EEDI Formula

*
j 1 i 1 j 1 i 1 i 1 i 1


1. Transport Work
Weight : at the maximum design load condition
Transport work can be represented by Weight and Speed of the ship. Speed : at 75% shaft power (MCR)

For cargo ship, it is obtained by multiplied *Deadweight tonnage and Speed of the ship. (ex. Gas/Oil carrier)
(But, for container ships, weight is 65% of the ship’s deadweight)

For passenger ship, it is obtained by multiplied Gross tonnage and Speed of the ship. (ex. Ro-ro passenger ship)

*Definition of ‘Deadweight’

Deadweight = displacement at deepest operational draught condition – displacement at lightship condition

Design draft? or Scantling draft?

IMO EEDI Formula

*
j 1 i 1 j 1 i 1 i 1 i 1


1. Transport Work

fi - Capacity factor for any technical /regulatory limitation on capacity,
and can be assumed one (1.0) if no necessity of the factor is granted

fw - Non-dimensional coefficient indicating the decrease of speed in representative sea conditions
(파도의 높이나 주기 또는 풍속 등의 해양 환경에 의한 선체 속도 감소를 고려하는 무차원수)

By 2.9.3 (MEPC.1/Circ. 681 ANNEX, Page 6),
fw should be taken as one (1.0) until Guidelines for ship-specific simulation or fw table/curve becomes available.

Where? How?

아직 지침이 확정되지 않아 1.0으로 가정
(‘IMO의 선박기인 CO2 배출 규제 동향 및 고찰’ 참고)

Appendix I (IMO MEPC.1 / Circ.681, 17 August 2009, Page 3)
 Capacity correction factor fi for ice-classed ships

fi - Capacity factor for any technical /regulatory limitation on capacity,
and can be assumed one (1.0) if no necessity of the factor is granted

For further information on approximate correspondence between ice classes, see HELCOM Recommendation 25/7

IMO EEDI Formula

*
j 1 i 1 j 1 i 1 i 1 i 1


2. CO2 emission by main
engine
CF - Non-dimensional factor to calculate emission of CO2 according to consumption of fuel oil

SFC ME - Specific Fuel oil Consumption, measured in g/kWh, at the engine 75% of MCR
PME - Power of Main Engine, measured in kW. Specifically, 75% power of MCR
after having deducted any installed shaft generators
▶More details, in next page

 ME - Variables about Main Engine

 AE - Variables about Auxiliary Engine

IMO EEDI Formula

*
j 1 i 1 j 1 i 1 i 1 i 1


engine
PME - Power of Main Engine, measured in kW. Specifically, 75% power of MCR
after having deducted any installed shaft generators

PME 0.75 ( MCRME PPTO )

PPTO - 75% output of each shaft generator Shaft generator : 축의 회전을 이용하여 전기를 얻는 장비
(발전 시설이므로 CO2 방출을 감소시키는 영향으로 생각)

Cf. Shaft motor (corresponding with PPTI) : Shaft generator를 통해 발생된 에너지를 이용하여 다시 축을 회전시키는 동력기
(다시 에너지를 소비시키므로, CO2 방출을 증가시키는 것으로 생각)

Appendix II (IMO MEPC.1 / Circ.681, 17 August 2009, Page 3)
 To understand about calculating PME by graph

*
j 1 i 1 j 1 i 1 i 1 i 1


MCRME (designed with shaft generator)
=MCRME0 + PPTO

MCRME0 (designed without shaft generator)
=MCRME - PPTO

PME (75% of MCRME0)
=0.75 x (MCRME – PPTO)

IMO EEDI Formula

*
j 1 i 1 j 1 i 1 i 1 i 1


engine
fj - Correction factor to account for ship specific design elements

구체적으로 어떤 수치들을 고려해야 할 지 설명이 부족하여 구체화시킬 필요가 있다.
(Ice classes 선박 중에서도 탱커, 건화물선, 일반 화물선의 3종류에 대한 가중치 계산 식만 첨부됨)

선종 특유의 수정계수로 현재 논의 중이며, 빙해지역을 운항하는 선박일 경우에만 계산된 값을 쓰며 그 이외는 1.0으로 둔다.

Appendix III (IMO MEPC.1 / Circ.681, 17 August 2009, Page 3)
 Correction factor for power fj for ice-classed ships

fj - Correction factor to account for ship specific design elements

For further information on approximate correspondence between ice classes, see HELCOM Recommendation 25/7

IMO EEDI Formula

*
j 1 i 1 j 1 i 1 i 1 i 1


3. CO2 emission by auxiliary
engine
*If part of the Normal Maximum Sea Load is provided by shaft generators, SFCME may – for that part of the power – be used instead of SFCAE

CF - Non-dimensional factor to calculate emission of CO2 according to consumption of fuel oil

SFC AE - Specific Fuel oil Consumption, measured in g/kWh, at the engine 50% of MCR
For ships where the PAE calculated by 2 formulas below is significantly different from the total power used at normal seagoing,
SFCAE is that recorded in the EIAPP Certificates for the engines at 75% of MCR power (ex. Conventional passenger ships)

PAE - Required auxiliary engine power to supply maximum sea load including necessary power for propulsion.

IMO EEDI Formula

*
j 1 i 1 j 1 i 1 i 1 i 1


engine
PAE - Required auxiliary engine power to supply maximum sea load including necessary power for propulsion.
nME
• For cargo ships with a main engine power of 10000kW or above PAE 0.025 MCRME (i ) 250
i 1

nME
• For cargo ships with a main engine power below 10000kW PAE 0.05 MCRME (i )
i 1

For ships where the PAE calculated by 1 or 2 formulas above is significantly different from the total power used at normal seagoing,
in case of passenger ships, the PAE should be estimated by the consumed electric power (excluding propulsion) in conditions
when the ship is engaged in a voyage at reference speed as given in the electric power table, divided by the weighted average
efficiency of the generators

IMO EEDI Formula

*
j 1 i 1 j 1 i 1 i 1 i 1


engine
PPTI - 75% of the rated power consumption of each shaft motor divided by the weighted averaged efficiency of the
generators (에너지를 소비시키므로, CO2 방출을 증가시키는 것으로 생각)

Shaft motor : 기존의 발전 시설을 이용하여 축의 회전을 돕는 장치

If the chain efficiency of the shaft motor is given in a verified document, the shaft motor’s chain efficiency may be taken into
consideration to account for the energy losses in the equipment from the switchboard to the shaft motor.

IMO EEDI Formula

*
j 1 i 1 j 1 i 1 i 1 i 1


3. CO2 reduction due to innovative energy efficient technology

Peff - 75% of the main engine power reduction due to innovative mechanical energy efficient technology

PAEeff - Auxiliary power reduction due to innovative electrical energy efficient technology measured at P ME

f eff - Availability factor of each innovative energy efficiency technology.
For waste energy recovery system, feff should be one (1.0)
How can I know?

EEDI formula

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EEDI formula