Uncertainty Analysis of Methods Used to Measure Ship Fuel Oil Consumption
Year: 2018 Language: English Author: J. Travis Hunsucker, Dylan Przelomski, Alex Bashkoff, John Dixon Genre: Research papers Publisher: Shipwright LLC Format: PDF Quality: eBook Pages count: 99 Description: The International Maritime Organization (IMO) has been actively estimating the CO 2 emissions from shipping for over the past decade. The results have been published in the First, Second, and Third Greenhouse Gas Studies (IMO 2015). Amendments to MARPOL Annex VI entering into force on 1 March 2018 will require ships to submit annual fuel oil consumption data to the IMO. The three most widely used methods for collecting data on annual fuel oil consumption are the bunker delivery note (BDN), monitoring tank level indicators (TLI), and using flow metering. The IMO convened this study to examine the uncertainty for each of these methods. The study estimated the uncertainty for each of these methods using 550,000 tonnes of measured fuel oil consumption from approximately 46 ships owned or operated by three companies. Key Findings 1. Annual fuel oil consumption determined from BDN and TLI data were in close agreement; whereas, the values determined from flowmeter data were systematically lower with the differences larger than what can be reasonably associated with fuel oil processing. The relatively large variance of the flowmeter data when compared to the BDN and TLI data suggest that the flowmeter data contain considerable amounts of random error. 2. An uncertainty analysis at a 95% confidence interval estimated that for all of shipping, the annual HFO fuel consumption determined from TLI and flowmeter data would have the following differences when compared to BDN data. • TLI: 0.33% ± 1.8% • Flowmeter: -12% ± 6.5% It is unknown if the relatively poor agreement of the flowmeter data in comparison to BDN and TLI sources are a coincidental artifact unique to these companies or if these findings are emblematic of accuracy problems observed in other types of shipboard data. 3. Combining the results with the literature survey for this study, the overall uncertainty for each of the fuel oil measurement methods was estimated as follows: • BDN: 3% for HFO and MGO/MDO • TLI: 5% for HFO and MGO/MDO • Flowmeter: 8% for HFO and 10% for MGO/MDO
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Uncertainty Analysis of Methods Used to Measure Ship Fuel Oil Consumption
Language: English
Author: J. Travis Hunsucker, Dylan Przelomski, Alex Bashkoff, John Dixon
Genre: Research papers
Publisher: Shipwright LLC
Format: PDF
Quality: eBook
Pages count: 99
Description: The International Maritime Organization (IMO) has been actively estimating the CO 2 emissions from shipping for over the past decade. The results have been published in the First, Second, and Third Greenhouse Gas Studies (IMO 2015). Amendments to MARPOL Annex VI entering into force on 1 March 2018 will require ships to submit annual fuel oil consumption data to the IMO.
The three most widely used methods for collecting data on annual fuel oil consumption are the bunker delivery note (BDN), monitoring tank level indicators (TLI), and using flow metering. The IMO convened this study to examine the uncertainty for each of these methods.
The study estimated the uncertainty for each of these methods using 550,000 tonnes of measured fuel oil consumption from approximately 46 ships owned or operated by three companies.
Key Findings
1. Annual fuel oil consumption determined from BDN and TLI data were in close agreement; whereas, the values determined from flowmeter data were systematically lower with the differences larger than what can be reasonably associated with fuel oil processing. The relatively large variance of the flowmeter data when compared to the BDN and TLI data suggest that the flowmeter data contain considerable amounts of random error.
2. An uncertainty analysis at a 95% confidence interval estimated that for all of shipping, the annual HFO fuel consumption determined from TLI and flowmeter data would have the following differences when compared to BDN data.
• TLI: 0.33% ± 1.8%
• Flowmeter: -12% ± 6.5%
It is unknown if the relatively poor agreement of the flowmeter data in comparison to BDN and TLI sources are a coincidental artifact unique to these companies or if these findings are emblematic of accuracy problems observed in other types of shipboard data.
3. Combining the results with the literature survey for this study, the overall uncertainty for each of the fuel oil measurement methods was estimated as follows:
• BDN: 3% for HFO and MGO/MDO
• TLI: 5% for HFO and MGO/MDO
• Flowmeter: 8% for HFO and 10% for MGO/MDO
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