Global Warming and Impact on ITTC Activities - Energy Saving by Ship - - PowerPoint PPT Presentation

Global Warming and Impact on ITTC Activities

• Energy Saving by Ship Hydro-Aero Dynamics-

National Maritime Research Institute

Director of Project Teams of Ship Performance Index

Noriyuki Sasaki

Contents

• 1. CO2 Emission Index - Japanese Proposal -
• 2. Trend of performance of ships
• 3. Energy saving devices
• 4. Simple evaluation method of actual sea

performance at initial design phase

• 5. Conclusions

排出量(百万トン)

2,000 4,000 6,000 8,000

アメリカ 中国 ロシア 日本 インド ドイツ 船舶 イギリス カナダ 韓国 イタリア メキシコ フランス オーストラリア

CO2 Emission from Ships at Operation

• 出典）EDMC／エネルギー・経済統計要覧2007年版

・CO2 emission from all ships in the world corresponds to emission from Germany ・CO2 emission from ships tends to increase with growing market of world shipping trade

MEPC57 agreed that the intersessional working group meeting on GHG in Oslo, Norway, should discuss the development of a CO2 design index for new ships.

CO2 Emission Index- Japanese Proposal to IMO

ANNEX 5 Draft Guidelines on the Method of calculation of the new ship design CO2 index The attained new ship design CO2 index is a measure of ships CO2 efficiency and is:

W ref NAE i AEi AEi FAEi L k k NME i MEi MEi FMEi M j j

f V Capacity P SFC C f P SFC C f index CO design ship New × × ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ + ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ =

∑ ∏ ∑ ∏

= = = = 1 1 1 1 2

CO2 from main engine CO2 from auxiliary engine

• dead weight
• total volume of cargo tanks
• gross tonnage

design ship speed

speed loss actual speed performance

9 fW is a non-dimensional coefficient indicating the decrease of speed in representative sea conditions of wave height, wave frequency and wind speed (e.g., Beaufort Scale 6), and should be determined as follows: . 1 It can be determined by conducting the ship-specific simulation of its performance at representative sea conditions. The simulation methodology shall be prescribed in the Guidelines developed by the Organization and the method and outcome for an individual ship shall be verified by the Administration or an

• rganization recognized by the Administration.

2 In case that the simulation is not conducted, fW value should be taken from the “standard fW ” table/curve. A “Standard fW ” table/curve, which is to be contained in the Guidelines, is given by ship type (the same ship as the “baseline” below), and expressed in a function of the parameter of Capacity (e.g., DWT). The “Standard fW ” table/curve is to be determined by conservative approach, i.e., based on the data of actual speed reduction of as many existing ships as possible under the representative sea conditions

CO2 Emission Index- Japanese Proposal to IMO

Similar System to Car FOCR Index

Measure Fuel Oil Consumption Rate under metropolitan driving modes

Trend of CO2 Emission from Ships

• 170 vessels built by Japanese Shipyards
• Categorized by ship 8 types (Tanker,Container,PCC,BC,etc)
• Fuel oil consumption per traffic volume (FOC/(Capacity*Vs))

are investigated

50,000 100,000 150,000 200,000 250,000 300,000 100 200 300 DW Loa bulk car cargo container

• il
• re

ro-ro その他

Relation between Loa(m) and DW(ton)

container tanker

10,000 20,000 30,000 40,000 50,000 60,000 70,000 50,000 100,000 150,000 200,000 250,000 300,000 MCR(kw) DW bulk car cargo container

• il
• re

ro-ro その他

Relation between DW(ton) and PMCR (kw)

Relation between DW(ton) and PMCR (kw) (Container)

10,000 20,000 30,000 40,000 50,000 60,000 70,000 20,000 40,000 60,000 80,000 100,000 120,000

DW(ton) PMCR (kw)

50 100 150 200 250 300 350 1973 1978 1983 1988 1993 1998 2003 2008 100 150 200 250 300 350 400 1973 1978 1983 1988 1993 1998 2003 2008

Tanker Container

Trend of Ship Length (Lpp) 1975-2005

VLCC AFRAMAX PANAMAX

ULCC

13.5 14 14.5 15 15.5 16 16.5 17 1970 1975 1980 1985 1990 1995 2000 2005 2010

Tanker

15 20 25 30 1973 1978 1983 1988 1993 1998 2003 2008

Container

Trend of Ship Speed (kts) 1975-2005

Trend of Design Froude Number 1975-2005

0.150 0.200 0.250 0.300 0.350 1973 1978 1983 1988 1993 1998 2003 2008

0.1 0.125 0.15 0.175 0.2 1970 1975 1980 1985 1990 1995 2000 2005 2010

Tanker Container

ULCC

0.05 0.1 0.15 0.2 1973 1978 1983 1988 1993 1998 2003 2008

Trend of FOC Index of Large Tankers built by Japanese Ship Yards

sec) / ( * / m ton day kg

turbine

13.5 14 14.5 15 15.5 16 16.5 17 1970 1975 1980 1985 1990 1995 2000 2005 2010

Tanker

Correction of Vs Correction of Vs + ship length

0.100 0.150 0.200 0.250 0.300 0.350 0.400 0.450 1973 1978 1983 1988 1993 1998 2003 2008

Trend of FOC Index of Large Containers built by Japanese Ship Yards

sec) / ( * / m ton day kg

15 20 25 30 1973 1978 1983 1988 1993 1998 2003 2008

Container

Conclusions 1

• Both container ships and tankers, FOC index trend

is almost the same except 1995 after

• The different tendency may be brought by the fact

that there are no effective energy saving devices for high speed containerships.

• It is also obvious that design ship speed of container

ship is not so reliable compared with tanker’s case.

total loss

Energy Loss of a conventional ship

wave resistance momentum loss viscous loss rotational loss rudder resistance

viscous resistance

momentum loss viscous loss rotational loss rudder resistance

Energy Loss of a conventional ship

propulsion loss

Recovered by Propeller Thrust deduction

Energy Loss at Ship Navigation

wind resistance

So complicated !

LV- LV-Fin (IH in (IHI) 1995 ) 1995 DPF (Sum F (Sumitomo) 1992 mo) 1992

Horizontal Fin in front of a propeller

• 1. Pressure recovery by preventing down flow
• 2. Induction of bilge vortex to propeller disc

SSD SSD ( (Universal al) SILD SILD (Su (Sumitom mitomo )

• )

Accelerating duct in front of a propeller

• 1. Pressure recovery by preventing down flow
• 2. Thrust due to duct
• 3. Induction of bilge vortex to propeller disc

Scale effect on SILD Performance

• 0.01

0.00 0.01 0.02 0.03 0.02 0.04 0.06 Δw Δ(1-t) Small Model Large Model

SHIP

Scale Effect of energy saving duct

Lpp=2m Lpp=8m Lpp=250m 1-2% 4-5% 7%

Improvement of (1-t) may be

• riginated from reduction of section

drag of duct due to Rn effect.

(average of 12ships with & 10 ships w/o)

Magnitude of Energy Saving for each device

Recovery of Propeller Energy Loss Reduction of Hull/Rudder resistance & Duct Thrust

２ ％ ３ ％ ４ ％ ５ ％ ６ ％ ７ ％ ８ ％

Energy saving device in future

Conclusions 2

• Owing to effective energy saving devices invented by

shipyards, FO index of tankers/bulk carriers were much improved in these 20 years.

• Energy saving device in future will have multifunction

such as a duct installed in front of a propeller

• CFD will be a good tool to investigate mechanism

however, it will be another several years to utilize as a design tool.

• It is very regrettable that there are no effective energy

saving devices for containerships which are the most important ships from a global warming view point.

4 2 4 Wave height（ｍ） Speed Loss(Knot ）

◆ Shipyard A ▲ Shipyard B ○ Shipyard C ■ Shipyard D

Calm Sea

Example of Ship Performance at Actual Sea

• Speed loss is not the same even if the ships was designed under

the same specification

2 Due to ship design

速力変更

ハイブリッド計算手法 Detail of Computation Flow

Tank test Calculation Design Index SHP = constant Yes

Resistance/Propulsion Test in still water

Resistance in still water air resistance Total resistance Required thrust thrust deduction Propeller loading Propeller Efficiency Propeller efficiency relative rotative efficiency Hull efficiency Propulsive Effciency Delivered Power Shaft Power SHP(wave)＝SHP

Speed Loss

Ship motion in regular wave Resistance in regular wave spectrum

• Resist. in short crest irregular wave

Effective horse power M/E performance Fuel Oil Consumption Ship Speed =const BF Speed Loss)

Iterated Process

Linearization 2

Simplified Method

波浪中抵抗増加計算 船体斜行・あて舵計算 波浪中自航計算 波浪中馬力計算 波浪中船速低下計算 主機燃料消費 理論計算の補正

• Cal. of Resistance in Waves

Effect of Wind Resistance Propulsive Efficiency Required Power in Waves Speed Loss due to Waves Fuel Oil Consumption Correction based on Model Test Design Index of Ship Performance

Linearization 1

hull Form

J

KT KQ

POWC

Simplified Method can be used at initial design phase where we hardly get the detailed information for the designed vessel.

平水中模型試験 正面規則波抵抗試験 Resistance Test Resistance Test in Regular Wave

Empirical Formula ) 1 ( 2 1 *

8 . 2 2 1 B a

Fn C BBfcp g C Raw + = ζ ρ

Simplified Method by EXCEL Calculation

Head Wind 13.50 14.00 14.50 15.00 15.50 16.00 16.50 1 2 3 4 5 6 7 8 Beaufort Scale Ship Speed(kts) Voyage Data CAL by Hope

Simplified Method of Added Resistancein Wave

kind of Ship Container Capacity 6500 TEU Lpp 300 m B 40 m D 24 m ｄ 14 m Cb 0.65 Disp 111930 ton Cp 0.658 LCB 0.59 %Lpp Af 1548 m**2 Dp 8.8 m 1-t 0.83 1-w 0.73 Vs 26.0 24.7 23.4 kts EHP 37,735 30,926 26,064 KW BHP 51,786 41,981 35,195 KW Cal of Ship Speed in actual sea Vs 26.0 24.7 23.4 Ro 287790 248268 220864 Cp 0.658 δCp 0.0285 Cpf 0.644 Bfcp2 0.034 Fnb 0.676 0.642 0.608 C1 1.00 C2 31.28 Raw(regular) 37210 35776 34328 Raw 18605 17888 17164 C0 0.60 Raa 28370 27406 26442 To 345403 297970 265080 To+δT 401782 352331 317415 Ct 1.140 1.090 1.080 Ct' 1.326 1.289 1.293 ηo'/ηo 0.975 0.973 0.971 929.8008 BHP' 61762 51004 43388 δVs

• 1.19

Vs (result) 24.8 δP'/P 19% 21% 23% fw 0.954 Power Curves(calm)

Input items (1) Principal dimensions of ship (2) Power curves (3 points) (3) Self propulsion factors (4) Frontal area of superstructure

Effect of measurement position on wind velocity

Conclusion

• Design Index of CO2 emission for individual ship was proposed to IMO

and this proposal will be accepted

• Simulation or prediction tool for CO2 emission at actual sea is very

important and the tool should be simple and robust.

• New idea of energy saving device for high speed ship such as

containership is burning issue.

• Energy saving devices for slow speed vessels such tankers should be

deeply investigated. Especially, scale effect and performance in wave are important.

• Resistance increment due to wind at navigation is not clear and full

scale measurement will help us to understand.