Power Barge

DEFINITION OF TERMS Air-Fuel Ratio:

The ratio of air weight to fuel weight consumed in an internal combustion engine or furnace.

ASTM

American Society for Testing Materials. Grade and quality specifications for petroleum products are determined by ASTM in test methods

Barrel

A unit of volume measurement used for petroleum and its products. 1 barrel = 42 U.S. gallons.

Blender

A device for mixing two fuel oils to achieve a less viscous and more uniform fuel.

Blending

Mixing of two compatible fuels having different properties in order to produce an intermediate fuel.

Catalyst

A substance which promotes a chemical reaction, but does not itself enter into the reaction.

Catalytic Fines

Hard, abrasive crystalline particles of alumina, silica, and/or alumina silica that can be carried over from the fluidic catalytic cracking process of residual fuel stocks.

Cetane Index

An empirical measure of ignition quality. Defined as the percentage by volume of cetane in a mixture of cetane and methyl naphthalene which has the same ignition quality when used in an engine as a fuel under test.

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Clarifier

A machine used for a liquid-sludge separation in which the particles with a higher specific gravity are separated from the lower specific gravity of the liquid. A clarifier bowl has one outlet for the light phase oil; the heavier phase particles are retained on the bowl wall.

Cloud Point

Temperature at which wax begins to crystallize from a distillate fuel.

Cracked

Refers to a petroleum product produced by a secondary refining process, such as thermal cracking or vis-breaking processes, which yield very low quality residua.

Flash Point

The lowest temperature at which a liquid will generate sufficient vapor to flash when exposed to a source of ignition.

Fuel Oil

The heavy distillates from the oil refining process; used as fuel for power stations, marine boilers.

Fungible

Interchangeable. Products which can be commingled for purposes of pipeline shipment.

Gasoil

Designation for No. 2 heating oils and diesel fuels. A clean distillate fuel oil.

Heavy crude

Crude oil with a high specific gravity and a low API gravity due to the presence of a high proportion of heavy hydrocarbon fractions and metallic content.

Homogenizer

A mechanical device which is used to create a stable, uniform dispersion of an insoluble phase (asphaltenes) within a liquid phase (fuel oil). 2|Page

Layering

This occurs in tanks when a high density fuel is mixed with a low density fuel.

Lifting

Refers to tankers and barges taking on cargoes of oil or refined product at a terminal or transshipment point.

Light crude

Crude oil with a low specific gravity and high API gravity due to the presence of a high proportion of light hydrocarbon fractions and low metallic content.

Light Ends

The more volatile products of petroleum refining; e.g., butane, propane,gasoline.

Long Ton

An avoirdupois weight measure equaling 2,240 pounds.

Marine Diesel Oil (MDO) Marine Diesel Oil (MDO) is a middle distillate fuel oil which can contain traces to ten percent (10%) or more residual fuel oil from transportation contamination and/or heavy fuel oil blending. The MDO does not require heated storage. Metric Ton

A weight measure equal to 1,000 kilograms, 2,204.62 pounds, and 0.9842 long tons.

Middle Distillate

Term applied to hydrocarbons in the so-called “middle range” of refinery distillation. Examples are heating oil, diesel fuels, and kerosene.

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Motor Gasoline

A complex mixture of relatively volatile hydrocarbons with or without small quantities of additives that have been blended to form a fuel suitable for use in spark-ignition engines.

Oil

Crude petroleum and other hydrocarbons produced at the wellhead in liquid form.

Olefins

Class of unsaturated paraffin hydrocarbons recovered from petrol. Typical examples include butene, ethylene and propylene.

Petrochemical

An intermediate chemical derived from petroleum, hydrocarbon liquids or natural gas, e.g., ethylene, propylene, benzene, toluene and xylene.

Petroleum

A generic name for hydrocarbons, including crude oil, natural gas liquids, natural gas and their products.

Polymerization

Process of combining two or more simple molecules of the same type, called monomers, to form a single molecule having the same elements in the same proportion as in the original molecules but having a different molecular weight. The product of the combination is a polymer.

Pour Point

Lowest temperature at which an oil will pour or flow under certain prescribed conditions.

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Residual Fuel Oil Heavy fuel oils produced from the non-volatile residue from the fractional distillation process. Heavy oils that are “leftovers” from various refining processes. Heavy black oils used in ships’ boilers and in heating plants.

Sludge

Deposits in fuel tanks and caused by the presence of wax, sand, scale, asphaltenes, tars, water, etc.

Solvent

A substance, normally a liquid, which is capable of absorbing another liquid, gas or solid to form a homogeneous mixture.

Specific Gravity

The ratio of the density of a substance at a particular temperature to the density of water at 15 degrees Centigrade

Static Mixer

A motionless mixer which has a series of fixed, geometric elements enclosed within a tubular housing. The internal elements impart flow division and radial mixing to the media flowing through the housing to produce a uniform dilution of the production.

Straight-Run

Refers to a petroleum product produced by the primary distillation of crude oil and free of cracked components.

Sulfur

An element that is present in crude oil and natural gas as an impurity in the form of its various compounds.

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Introduction Power Barges are marine vessels in which a power plant is installed for the purpose of energy generation. Existing large bulk carriers are fitted with reciprocating engines, large-bore dual-fuel diesel engines that run on heavy fuel or natural gas to generate electricity. High demand for Power Barges is at its peak due to its short construction cycles, mobility and its minimal space requirement. For many years it has been very competitive against its land-based equivalents due to several advantageous points no other power plants has. Amongst its many advantages are as follows. (Power Barge Corporation, 2004) The power barge is rated at 70 MW which is composed of 20 main diesel engines, 4 MW each, of which 2 are reserves. The design of a power barge is composed of the tank farm, the cooling system, the air starting system, the auxiliary equipment and mooring.

Figure 1 Power Barge

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Faster deliveries and higher quality construction resulting in an increased availability and reliability;

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Shop-built in a controlled environment by trained qualified labor workforce;

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Capable of pre-designed modification from fast track simple cycle operation to combined cycle mode with minimal operational impact; and

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Easily transported between sites creating flexibility to demand growth and location. 6|Page

Engine The most integral part of a Power Barge is the diesel engine. It is considered as most important part of the barge since this is where power generation takes place. In choosing a diesel engine, the peak load of the design should be met therefore the summation of the power capacity of the engines to be used can generate the desired amount of energy. Diesel engines used on power barges may differ on capacity or output. Other specifications may also vary such as fuel consumption, lube oil consumption, rated speed, bore diameters and stroke as specified by the manufacturer. The chosen diesel engine to be used in this power plant design is presented in Table 3.1. The height should always be considered in choosing a diesel engine since the power barge needs to be in complete balance all the time. The engine should not be too high and must be equally distributed once in the barge.

DIESEL ENGINE Engine Output (KW) Generator Output (KW) Fuel Oil Consumption (g/KW-h) MCR (%) Heat Rate (KJ/KW-h) Specific Lube Oil Consumption (g/KWh) Engine Type Specific Reference Change Air Temperature Before Cylinder (0C) Lower Heating Value (KJ/Nm3) Compressor Air Consumption per Start Rated Speed (rpm) No. of Cylinder Dry Mass Bore (mm) Stroke (mm) Tolerance (%) Weight (Tons)

4,230 KW 4,061 KW 183.5 g/KW-h 100% 8,083 KJ/KW-h 8,420 KJ/KW-h 0.09 - 0.19 g/KW-h 43 0C 28000 KJ/Nm3 70 psig required 0.32 m3 750 rpm 16 62.2 280 mm 320 mm 5% 240 tons

Table 1 Chosen Diesel Engine

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Figure 2: Diesel Engine

A (mm)

6,116 mm

B (mm)

3,822 mm

C (mm)

9,938 mm

Height (mm)

3,449 mm

Width (mm)

2,470 mm

Table 2 Diesel Engine Dimensions

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FUEL TREATMENT AND CONDITIONING Power Barges supply power round the clock, meaning 24 hours a day, therefore diesel engines run in the same amount of time Diesel Engines run on diesel for initial start-up and shutdown and switches to bunker fuel. The amount of diesel and bunker should be determined to compute for the fuel tank dimensions. Diesel Engines run on bunker oil and diesel as supply fuel. In the calculation of fuel consumption, a designer must be mindful of the Lower Heating Value, Heat Rate, Specific Fuel Oil Consumption and the Power rating of the Generating Unit as specified in the engine specification (4,061 KW).

Element % Carbon % Hydrogen % Oxygen % Nitrogen % Sulfur % Ash

Ultimate Analysis Bunker Diesel 0.857 0.86208 0.117 0.1246 0.003 0.00148 0.004 0.00172 0.0195 0.01 0.0005 0.00012

Table 3 Diesel and Bunker Oil Ultimate Analysis

Fuel treatment is necessary when operating Diesel Engines. Fuel must be transferred, heated, filtered and purified in order to prepare it for the best possible properties for injection to the engine and to avoid contaminants on the fuel that can lead to some fatal consequences. It is a requirement in all power plants that uses diesel engines for power generation. The purpose of this system is three-fold: 1) cleaning of the fuel oil by removal of water, solids, and suspended matter to protect the engine from excessive wear and corrosion; 2) conditioning of the fuel oil to prepare for best possible properties for injection to the engine and a good combustion; and 3) to take care of oily sludge streams from separators, self-cleaning filters etc, with the task to reduce the sludge volume which has to be landed or incinerated, to recover usable fuel oil, and to extract water to be transferred to the bilge water system.

COOLING SYSTEM 9|Page

Lubricating Oil Heavy Working Industrial application running constantly under high pressure and hot temperature need a proper lubrication to protect the working surface from corrosion and keep the efficiency of the engine. According to the engine manufacturer if the sulfur content is less than 0.5 % BN20 lubricating oil should be used. The reduced sulfur computed was 0.16% and the specific lube oil consumption is 0.09 - 0.19 g/KW-h Table 6 shows the selected Lubricating oils specifications. Typical Properties Oil Type SAE Viscosity Grade

AeroShell 10W-40 Full synthetic-hydrocardbon Multigrade 10W-40

Density @ 150C , kg/l Base Oil Viscosity mm2/s @1000C @400C Viscosity Index Pourpoint , 0C Total base number , mgKOH/g

0.859 14.6 93.0 Above 160 -38 25

Sulphated Ash Content , %m

1.9

Table 4 Lubricating Oil Specification

Consumption , kg/hr

3.76

Filling Volume , m3

0.16

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Total Filling Volume Required , m3

0.54

Total Consumption per hour , m3/hr

0.02

Total Consumption per 30 days , m3/month

14.4

Table 5 Filling Volumes and Consumption

Knowing the total capacity of lubricating oil needed, we can now choose the Lubricating module that will guarantee that lube oil is cleaned before it recirculates inside the engine. Capacity , liters

16,000

Dimensions (L X W X H) , m

(5 x 3.5 x 3.5)

Weight(Without Oil) , tons

10.5

Table 6 Lubricating Oil Module

Black Start Engine The Black start engine initiates the initial power to the compressor for the diesel engines to run. The capacity of the Black start engine depends on the required compressor rating and the lightings as used in the barge.

Figure 3 Black Start Engine

Diesel Generator Set Power Rating

990 kW

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Height

2337 mm

Width

1400 mm

Length

4207 mm

Weight

9.5 Ton

Table 7 Black Start Engine Specifications

AIR HANDLING SYSTEM The usual function of an air system is to transmit energy generated at a single source to different areas of a facility. The air receiver stores and delivers air pressure 12 | P a g e

when the compressor is not running, and also serves as a pulsation damper and moisture trap. In the case of a power barge, the air bottle is used to store pressurized air from the compressor to be used for starting the main diesel engines and any other equipment inside the power plant. The High compression pressures of the full diesel make it difficult to start even the smallest diesels by hand cranking and, in general, diesel engines must be started by a mechanical cranking system. Compressed air, electric cranking motors, and auxiliary gasoline engines are used. Large stationary diesels are started with air compressors. (Morse, 1932) In addition to compressed air for starting, the air injection types require an injection air system; also some solid injection types have a scavenging air system. Two or more compresses air storage tanks, or “bottles” are provided. A small compressor is installed either as a normal or emergency supply of compressed air to recharge the storage tanks. Starting air pressure needs to be 14 – 42 kg/cm 2. (Morse, 1932) Starting air compressors are to be of the water cooled, two stage type with intercooling as recommended by the engine manufacturer. According to the engine manufacturer, 0.32 m 3 of air is needed per start. In the design of the air stating system, a single compressor and air bottle is used to start multiple engines. Each set is composed of 5 engines. Therefore each air bottle should have at least 1.58 m3.

Air Compressor The size of the air bottle depends on the compressor unit chosen. Each type of compressor has a corresponding air receiver capacity which is also dependent on the amount of air. In choosing the compressor, the minimum requirement of 70 psig for the black start engine as stated in the machine specifications must be used as a basis.

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Figure 4 Water Cooled Air Compressor

Table 8 shows the compressor specifications of the chosen equipment. Air Compressor Pressure Volume Flow Rate Power No. of Cylinders Net Weight Full Load Speed Fuel Tank Capacity Fuel Consumption @ 0% Load Fuel Consumption @ 100% Load

100 psi 375 CFM 115 HP 4 1754 kg 2400 rpm 38 Gal 1.46 Gal/hr 5.34 Gal/hr

Table 8 Compressor Specifications

The compressor has a pressure of 100 psi and a volume flow rate of 375 CFM. The power of each compressor installed is 115 HP running at 2400 rpm.

Air Bottle Air Bottles serve as the air receiver from the air compressor before it enters the diesel engine. The size of the air compressor depends on the amount of air consumption per start. For a set of engines composed of 5 diesel engines, 1.58 m 3 is the minimum volume of the air receiver. Taking a factor of safety of 10% in consideration, 1.78 m3 is provided. Figure 5 shows the air receiver used in the power barge. 14 | P a g e

Figure 5 Air Receiver

There are also different kinds of compressor-engine configuration depending on the manufacturer. A sample design from the engine’s manufacturer is presented below.

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Figure 6 Air Starting System

Figure 6 shows the air system set-up provided by the engine manufacturer two air compressors, with automatic start and stop, maintain a starting air pressure of 70 psi in the starting air receivers. The main engine is supplied with 70 psi starting air directly from the starting air receivers. (MAN,2011) In the design, there would be one (1) compressor and one air receiver of air bottle per set of engines, each connected to 5 diesel engines. Therefore, a total of 4 compressors and 4 air bottles will be used with 2 compressors per barge.

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