scholarly journals ANALYSIS OF CORROSION DEPTH PERCENTAGE ON THE INNER BOTTOM PLATES OF AGING BULK CARRIERS WITH AN AIM TO OPTIMIZE CORROSION MARGIN

Brodogradnja ◽  
2021 ◽  
Vol 72 (3) ◽  
pp. 81-95
Author(s):  
Špiro Ivošević ◽  
◽  
Nataša Kovač ◽  
Nikola Momčilović ◽  
Goran Vukelić ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Alternative Energy ◽  
Structural Integrity ◽  
Linear Models ◽  
Metal Plate ◽  
Fuel Oil ◽  
Corrosion Depth ◽  
Structural Rules ◽  
Bulk Carriers ◽  
Simple Conversion

To ensure the better structural integrity and maximum safety of bulk carriers in the ship design phase, an appropriate corrosion margin is introduced by the classification societies, which should enable the exploitation of ships during the projected 25-year life cycle. The new Common Structural Rules introduce even higher corrosion margin value to ensure the structural integrity of the ship. This directly affects the increase in hull weight and thus the need for more total installed power and higher fuel consumption. Higher fuel consumption results in increased emissions which directly affects environmental pollution. For these reasons, efforts are being made to introduce alternative energy sources, cleaner fuel, ship weight reduction, and the overall economic efficiency of ships. Therefore, using experimental data collected on aging bulk carriers, the paper explores the corrosion margin reduction potential considering its impact on hull weight. Assuming that the corrosive processes occur after four years of operation, a linear model that describes the percentage of plate wear as a function of the as build-in the thickness of inner bottom plates (IBP) of fuel oil tanks (FOT) located on the double bottom of aging bulk carriers, is analyzed. Over the course of 25 years, the IBP segment was monitored on 36 different ships surveys. In this way, 520 input data describing the depth of corrosion were formed. At the same time, records were kept on the mean thickness of the original metal plate, which enabled systematization of the empirical database and grouping of measured values by intervals of original plate thicknesses, and simple conversion of corrosion depth into adequate percentage values. Depth corrosion percentages were represented by standard linear models known in the literature. Based on this analysis, representative numerical and graphical results were obtained. Conclusions from the paper can assist to optimize corrosion margin and the energy efficiency of future vessels.

scholarly journals ANALYSIS OF CORROSION DEPTH PERCENTAGE ON THE INNER BOTTOM PLATES OF AGING BULK CARRIERS WITH AN AIM TO OPTIMIZE CORROSION MARGIN

Brodogradnja ◽  
2021 ◽  
Vol 72 (3) ◽  
pp. 81-95
Author(s):  
Špiro Ivošević ◽  
◽  
Nataša Kovač ◽  
Nikola Momčilović ◽  
Goran Vukelić ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Alternative Energy ◽  
Structural Integrity ◽  
Linear Models ◽  
Metal Plate ◽  
Fuel Oil ◽  
Corrosion Depth ◽  
Structural Rules ◽  
Bulk Carriers ◽  
Simple Conversion

To ensure the better structural integrity and maximum safety of bulk carriers in the ship design phase, an appropriate corrosion margin is introduced by the classification societies, which should enable the exploitation of ships during the projected 25-year life cycle. The new Common Structural Rules introduce even higher corrosion margin value to ensure the structural integrity of the ship. This directly affects the increase in hull weight and thus the need for more total installed power and higher fuel consumption. Higher fuel consumption results in increased emissions which directly affects environmental pollution. For these reasons, efforts are being made to introduce alternative energy sources, cleaner fuel, ship weight reduction, and the overall economic efficiency of ships. Therefore, using experimental data collected on aging bulk carriers, the paper explores the corrosion margin reduction potential considering its impact on hull weight. Assuming that the corrosive processes occur after four years of operation, a linear model that describes the percentage of plate wear as a function of the as build-in the thickness of inner bottom plates (IBP) of fuel oil tanks (FOT) located on the double bottom of aging bulk carriers, is analyzed. Over the course of 25 years, the IBP segment was monitored on 36 different ships surveys. In this way, 520 input data describing the depth of corrosion were formed. At the same time, records were kept on the mean thickness of the original metal plate, which enabled systematization of the empirical database and grouping of measured values by intervals of original plate thicknesses, and simple conversion of corrosion depth into adequate percentage values. Depth corrosion percentages were represented by standard linear models known in the literature. Based on this analysis, representative numerical and graphical results were obtained. Conclusions from the paper can assist to optimize corrosion margin and the energy efficiency of future vessels.

scholarly journals A Probabilistic Method for Estimating the Percentage of Corrosion Depth on the Inner Bottom Plates of Aging Bulk Carriers

2020 ◽  
Vol 8 (6) ◽  
pp. 442
Author(s):  
Špiro Ivošević ◽  
Romeo Meštrović ◽  
Nataša Kovač
Keyword(s):  
Density Function ◽  
Statistical Approach ◽  
Statistical Tests ◽  
Probabilistic Method ◽  
Random Variable ◽  
Fuel Oil ◽  
Cumulative Density Function ◽  
Corrosion Depth ◽  
Bulk Carriers ◽  
Oil Tanks

This paper presents an approach for the model estimating the probabilistic percent corrosion depth for inner bottom plates of fuel oil tanks located in the double bottom of aging bulk carriers. Assuming that corrosion begins after four years of exploitation, a statistical approach to investigations on the ratio of the corrosion rate and the average initial inner bottom plate’s thickness of considered bulk carriers is given. We consider this ratio to be a random variable since it is included in the usual linear corrosion model. By applying adequate statistical tests to the available empirical dataset, three best fitted three-parameter distributions for estimating the cumulative density function and the probability density function of the random variable were obtained. These three distributions were further used to estimate the studied percentage of corrosion depth. Lastly, we present the corresponding numerical and graphical results concerning the obtained statistical and empirical results and give concluding remarks.

scholarly journals Neural Network Approach for Predicting Ship Speed and Fuel Consumption

2021 ◽  
Vol 9 (2) ◽  
pp. 119
Author(s):  
Lúcia Moreira ◽  
Roberto Vettor ◽  
Carlos Guedes Soares
Keyword(s):  
Neural Network ◽  
Fuel Consumption ◽  
Computing System ◽  
Fuel Oil ◽  
Network Computing ◽  
Peak Period ◽  
Neural Network Approach ◽  
Data Set ◽  
Navigation Data ◽  
Ship Speed

In this paper, simulations of a ship travelling on a given oceanic route were performed by a weather routing system to provide a large realistic navigation data set, which could represent a collection of data obtained on board a ship in operation. This data set was employed to train a neural network computing system in order to predict ship speed and fuel consumption. The model was trained using the Levenberg–Marquardt backpropagation scheme to establish the relation between the ship speed and the respective propulsion configuration for the existing sea conditions, i.e., the output torque of the main engine, the revolutions per minute of the propulsion shaft, the significant wave height, and the peak period of the waves, together with the relative angle of wave encounter. Additional results were obtained by also using the model to train the relationship between the same inputs used to determine the speed of the ship and the fuel consumption. A sensitivity analysis was performed to analyze the artificial neural network capability to forecast the ship speed and fuel oil consumption without information on the status of the engine (the revolutions per minute and torque) using as inputs only the information of the sea state. The results obtained with the neural network model show very good accuracy both in the prediction of the speed of the vessel and the fuel consumption.

POTENSI SUMBER BIOGAS BERBASIS TINJA PADA SUATU CLUSTER PERUMAHAN

2021 ◽  
Vol 4 (1) ◽  
pp. 33-39
Author(s):  
As Zhu Ra ◽  
Sudarti ◽  
Yushardi
Keyword(s):  
Alternative Energy ◽  
Fermentation Process ◽  
Developed Countries ◽  
Fuel Oil ◽  
Basic Material ◽  
Septic Tank ◽  
Exhaust Pipe ◽  
Human Waste ◽  
Methane Gas ◽  
The Future

Abstract: THE POTENTIAL OF BIOGAS SOURCES BASED ON REFERENCE IN A HOUSING CLUSTER. In the future there will be a shortage of fuel oil, as a result developed countries will begin to work on the management of use in replacing the problem of low fuel oil and shortage of LPJ gas in the future, one of which is to produce alternative energy using human waste as the basic material, usually called Bio- Gas / Bio-Fuel. However, the management system and processes still use septic tanks that absorb human waste. So the main material or human waste that can be made to generate alternative energy for general public needs, so that it is not wasted using existing disposal methods. This activity is an explanatory activity to describe the process of disposing of human waste in the process of the exhaust pipe equipment system for each house by accumulating it in the central disposal area for the fermentation process to produce methane gas which is converted into gas power to electricity. This invention is used to find out how to make biogas from human waste. The findings of the present invention show the addition of methane gas and a central septic-tank in several households. Key words: Energy, Alternative, Biogas, Human waste, Fermentation process, Biofuel Abstrak: Pada masa depan akan terjaddi kekurangan bahan bakar minyak, akibatnya wilayah negara maju memulai mengerjakan pengelolaan digunakan dalam menggantikan permasalahan sedikitnya BBM dan kekurangan gas LPJ pada masa depan nanti, salah satu yang dilakukan adalah memproduksi energi alternative dengan bahan dasar kotoran manusia biasanya dinamakan dengan Bio-Gas/Bio-Fuel. Akan tetapi, system pengelolaannya dan prosesnya masih menggunakan septik-tank yang meresap kotoran manusia. Jadi bahan utama atau limbah manusia yang sepatutnya dapat dibuat untuk penghasilan tenaga alternative untuk keperluan umum masyarakat, supaya tidak terbuang sia-sia menggunakan cara pembuangan yang ada. Kegiatan ini merupakan pada kegiatan eksplanatori berbuat untuk mendiskripsikan proses prosedur membuang kotoran manusia dalam proses system perlengkapan pipa pembuangan tiap-tiap rumah dengan dikomulatifkan di wardah pembuangan pusat untuk proses fermentasi untuk menghasilkan gas metana yang dirubah dalam tenaga gas ke listrik. Penemuan ini digunakan untuk mengetahui bagaimana cara membuat biogas dari kotoran manusia. Perolehan dari penemuan ini memperlihatkan penambahan gas metana dan sentral septik-tank pada beberapa rumah tangga. Kata kunci: Energi, Alternatif, Biogas, Kotoran manusia, Proses fermentasi, Biofuel

scholarly journals Analysis of Fairness Limit on Fuel Oil Consumption of TwoTail Test Based Excavator and Dump Truck A Case Study in PT XYZ

2020 ◽  
Vol 1 (1) ◽  
pp. 6-12
Author(s):  
Bella Puspa Octaviania ◽  
Supriyadi ◽  
Ambran Hartono
Keyword(s):  
Fuel Consumption ◽  
Statistical Approach ◽  
Fuel Oil ◽  
Dump Truck ◽  
Oil Consumption ◽  
Mining Operations

A lack of method to find out the fairness limit of fuel consumption in mining operations enables statistical approach with two-tail test be applied to observe the fairness limit of actual fuel oil consumption compared to the manual handbook of its equipment. Fuel consumption according to the manual handbook for EXCA LIEBHERR 9350 excavator is 207.23 liters/hour and EXCA HITACHI 2500 is 191.51 liters/hour, while CATERPILLAR 777D Dump Truck is 36-53 liters/hour consider as low, 53-73, 8 liters/hour medium, and 73.8-96.5 liters/hour as high. This statistical approach has been carried out after fulfilling the concept of mechanized earth-moving. As a result, the differences in fuel consumption of LIEBHERR 9350 and HITACHI 2500 are 3.72% and 3.26%, which are still in range of a reasonable fuel consumption limit, while CAT 777D operating on LIEBHERR 9350 and CAT 777D operating on HITACHI 2500, each shows a difference in fuel consumption. The differences are 29.65%, meaning that it has exceeded the reasonable limits of fuel consumption and 7.15%, meaning that it is still in range of a reasonable fuel consumption limit.

Analysis of Bolted Joints with Nonlinear Gasket Behavior

1980 ◽  
Vol 102 (3) ◽  
pp. 249-256 ◽  
Author(s):  
A. I. Soler
Keyword(s):  
Structural Integrity ◽  
Linear Models ◽  
Bolted Joint ◽  
Stress Strain ◽  
Highly Nonlinear ◽  
Nonlinear Stress ◽  
Joint Connection ◽  
Leak Tightness ◽  
Gasket Material ◽  
Full Face

Design methods for full face gaskets in bolted pressure vessel joints have received little attention in the literature. Such gasketed joints play a prominent role in attaching rectangular plan from water boxes to rectangular tubesheets in condenser water boxes. With higher cooling water pressures becoming evident due to cooling tower circuits, the water box-tubesheet structure, and its bolted joint connection requires rigorous analysis for both structural integrity and leak tightness. Although it is well known that gasket material has a highly nonlinear stress strain behavior, very few analyses are available to calculate and evaluate the effect of the nonlinear gasket behavior in a bolted joint connection. In this paper, an approximate method for simultaneously analyzing structural integrity and leak tightness of typical bolted flange connections with nonlinear gasket material is developed. The flange is modeled as an elastic element, the bolt is simulated by a linear spring with bending and extensional resistance, and the gasket is modeled by a series of nonlinear compression springs. A simple nonlinear stress-strain relation for initial loading and unloading of the gasket is developed based on experimental data. The analysis technique employs an incremental procedure which follows the configuration through preloading and pressurization and checks structural integrity and gasket leakage. To illustrate the method, a typical full face gasket and flange construction is studied, and the effect of gasket properties on the final state is investigated. A series of simulation results are obtained which illustrate clearly the effect of gasket prestrain, undersizing of bolts, and wall rotational resistance. Of particular importance is a simulation comparing results obtained using actual nonlinear gasket stress-strain data with results obtained using linear models for the gasket. It is demonstrated that for full face gasket configurations, simulation of the nonlinear behavior is required to achieve accurate results. The procedure developed in this work is ideal for optimization of flange gasket configurations because of its cost effectiveness while simultaneously evaluating the interaction between structural integrity and joint leak tightness.

PERFORMA GENERATOR HHO DALAM SISTEM BI-FUEL PADA SEPEDA MOTOR SEBAGAI BAHAN BAKAR ALTERNATIF

ROTOR ◽  
2017 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Ika Kusuma Nugraheni ◽  
Anggun Angkasa ◽  
Abdul Rahman Rifa’i
Keyword(s):  
Performance Analysis ◽  
Fuel Consumption ◽  
Alternative Energy ◽  
Fossil Fuels ◽  
Fossil Fuel ◽  
Sea Water ◽  
The Other ◽  
Engine Oil ◽  
Other Hand ◽  
Land Water

The increasing of vehicle uses will make the increasing in fuels consumption. In the other hand, the reserves of fossil fuels as a fuel in vehicles are always decreasing. In order to anticipate the lack of fossil fuels, there is some alternatives energy that has to substitute the fossil fuels. One of the alternative energy is HHO Gas. HHO gas is a gas that was produced by the electrolysis of water. Water as an abundant material in earth can be an alternative energy that replace or substitute fossil fuel. In this research, HHO gas will be used as a supplement in fuels. So the vehicles use two fuels (bi-fuel. )The aim of this research is to analyze the performance of uses HHO gas in vehicles. The HHO gas will be produced by different water, such as aquadest, land water, sea water. The performance analysis was focused in the fuel consumption and the efficiency of thermal engine oil. The analysis result shows that the addicted HHO gas can make the efficiency of fuel consumption better. The highest efficiency fuel consumption is in the fuel with HHO gas from aquadest (19.95%). But the best efficiency in thermal engine oil is in HHO gas from sea water (0.84 oC). Keywords: HHO, performance, engine, bifuel

Minimal Time Route Computation for Ships with Pre-Specified Voyage Fuel Consumption

2008 ◽  
Vol 61 (4) ◽  
pp. 723-733 ◽  
Author(s):  
S. J. Bijlsma
Keyword(s):  
Carbon Dioxide ◽  
Air Pollution ◽  
Fuel Consumption ◽  
Greenhouse Effect ◽  
Fuel Oil ◽  
Air Emissions ◽  
Combustion Engines ◽  
Heavy Fuel Oil ◽  
Additional Method ◽  
Minimal Time

The air pollution caused by the use of heavy fuel oil in shipping is a growing problem that is drawing increased attention. Methods have been developed to reduce air emissions from ships, more or less aimed at the choice of fuel and the related air emissions. However, the emissions of particulates, sulphur and carbon dioxide, which contribute to the greenhouse effect are not only related to the choice of fuel but also to the amount of fuel consumed in the combustion engines. This paper proposes an additional method that can contribute to the reduction of the air pollution from ships by decreasing the fuel consumption. This is done by specifying the amount of fuel that can be consumed on a specific ocean crossing and by computing a minimal-time route for that given amount of fuel, so decreasing the fuel consumption in a verifiable way.

A Car for the Nineties: BL's Energy Conservation Vehicle

1984 ◽  
Vol 198 (1) ◽  
pp. 21-31 ◽  
Author(s):  
C S King
Keyword(s):  
Middle East ◽  
Energy Conservation ◽  
Fuel Consumption ◽  
Fuel Oil ◽  
Vehicle Development ◽  
The Third ◽  
Third Phase ◽  
Noise Vibration ◽  
Whole Life Cost ◽  
Better Than

Several crises in the Middle East have resulted in the disappearance of cheap fuel oil. Further crises are possible and although considerable reserves exist, with the exception of the Middle East, production is bound to become more and more expensive. BL's answer is the conservation vehicle. Development ran through two preliminary phases, ECVI and ECV2, which were based on a small car prototype. The third phase ECV3, though profiting from the earlier vehicles, bears little resemblance to them; it is bigger, it shares few common parts and to a large extent is made from different materials. The objectives for the ECV are 0–60 mile/h acceleration in 12 s or less with an average fuel consumption of better than 50 mile/gal. It must be in no way inferior to existing medium sized family cars in performance, ride, handling, interior noise, vibration, safety and accommodation. It is designed for minimum whole life cost. This lecture describes the efforts made to meet these objectives.

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