Reducing Engine Noise

By Keith Henderson at September 19, 2010 10:48
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At this year's CIMAC conference Wärtsilä presented a paper following a five year research program on noise reduction of medium speed engines. The test engine used was a seven cylinder 32 series engine of  3.5MW at 750 rpm with 320 mm bore and stroke of 400 mm.
 
Changes made to the crankcase covers and camshaft covers included replacing the one piece cast aluminum covers by a two piece cast aluminum frame with bonded and bolted 2mm steel cover plate, giving greater rigidity and reducing noise radiation that brought the emitted sound level down by approximately 6dB(A). A multi-layer sandwich solution of fireproof fabric, mineral wool, aluminium plate and finally more fireproof fabric applied to the turbocharger casing and charge air cooler reduced emitted noise levels from these parts by 5dB(A).

Tests showed that 27 per cent of engine noise emanates from the top of the engine. Noise level from this area was reduced by placing an additional covering comprising a a 2 mm vibro-acoustically treated steel plate with a 1mm corrugated micro-perforated plate on top of the existing cylinder head valve covers.

It is proposed that these optional parts will be available for current and future Wärtsilä medium speed engines  providing a noise reduction of approximately 5dB(A).

Plug-in Shore Power

By Keith Henderson at September 18, 2010 12:57
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A major factor slowing down the more widespread use of plug-in shore power to permit cold ironing is the lack of a safe, troublesome and easy to use standard for the shore to ship connector. Further complicating the problem is the abundance of different voltage and frequency systems found on ships of different nations.

At the SMM exhibition in Hamburg last week a step closer to solving this problems was exhibited by the French company New Generation, Natural Gas abbreviated to NG2. The PLUG (Power Generation during Loading and Unloading) is a semi automatic system requiring only one sailor to operate it with no physical effort and to connect to the shore: no shore personnel is required.

The ship installation is sufficiently compact that it fits within one frame space and a watertight door closes off the system when not in use or at sea. At the shore end of things, a self sealing diaphragm closes off the shore connection preventing any contact with live parts. Lining up the ship and shore connector and mating of the connection is fully automatic. A torque meter monitors the forces on the power lines and if a preset level is reached the safe emergency release procedure is activated sounding an alarm, shutting off the electricity and releasing the power line all within 60 secs. Although the connector is standard it can be used for a variety of electric power systems, varying from 440 to 11,000 volts with a power from 300 kW to 12 MW.

Hydrogen Power

By Keith Henderson at September 18, 2010 06:04
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Cruising round the narrow canals of Amsterdam on a hot, airless, summer day sometimes involved passing through an exhaust cloud as the hundreds of boaters toured the sights.
In a bold attempt to cut down exhaust emissions to zero, a new canal cruise boat Nemo H2 has joined the fleet operated by Rederij Lovers, Amsterdam.

Designed and developed by the Dutch company Fuel Cell Boat BV the canal boat is similar to conventionally powered boats with panoramic windows but is of course, silent and produces zero emissions.

Main propulsion is provided by a single 75 kW Voith azimuth electric thruster in the stern, with an 11 kW electric bow thruster in the bow to facilitate getting round the 90 degree turns required when negotiating the narrow 16th century canals. Electric power is produced from twin 30 kW PEM fuel cells with a 70 kWh Li-phosphate battery. The fuel cells run on hydrogen stored in six cylinders at a pressure of 35 MPa with a total capacity of 24kg of gas. Maximum speed is 8.6 kts and autonomy at a mean speed of seven kts is nine hours.

Refueling at the base station is simple with a bayonet connector, similar to automotive LPG refueling and is completed in under 10 minutes. The battery can also be charged when alongside. The gas installation is safety approved by Germanischer Lloyd.

emissions. The 22m LOA vessel with 4,24m beam carries 86 passengers with a crew of two.
Completing the target of zero emissions, the hydrogen fuel is produced by electrolysis, using electricity generated from a windfarm in the North Sea.

photo courtesy of www.lovers.nl

Black Magic for Green Vessels

By Keith Henderson at September 05, 2010 18:43
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Following on from the design of his hybrid megayacht Transcendence, Richard Sauter the founder of Sauter Zero Carbon Design, is showing a way forward for commercial ships of the future featuring a design for a zero carbon vessel with greatly reduced emissions of greenhouse gases (GHG). Called Black Magic, she is a 4,000 ton solar hybrid vessel that claims to reduce GHG by 75 to 100 per cent compared to present vessels of this size by using currently available technology to capture energy from the sun, wind and waves.

The unusual wave piercing pentamaran hull is powered by several propulsion methods solely or in combinations. A large solar cell area of 2,000 square meters is sufficient to produce enough electrical power to the banks of lithium batteries to run the hotel load as well as allow the vessel to operate at her maximum speed of 16 kts. It also permits running in controlled areas such as harbors or inland waterways with zero emissions.

A high efficiency azimuth propulsion system drives counter rotating Contracted Loaded Tip (CLT) propellers. (These are propellers with a plate on the tip, perpendicular to the blade.)

Wind propulsion produced by three pairs of fully rotational wing sails can propel the ships at 10 kts and using an optional Sky Sail increase this to 12 kts.

Contributing to the low emission claims is the use of Mercedes-Benz BlueTEC® exhaust treatment on the diesel generators of the diesel electric propulsion system. It reduces NOx by using a two stage catalytic converter. The first converter traps the NOx, and then passes it to the second converter which then converts it to nitrogen (N2) and water (H2O). According to specifications there is an optional particulate filter and a Selective Catalytic Reduction (SCR) catalytic converter to convert remaining nitrogen oxides to nitrogen and water.

Automatic Engine Tuning

By 6x6volvo at August 27, 2010 18:02
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Automatic optimization of marine diesel engine performance using loop control of the cylinder pressure process has been under development for a number of years at both MAN Diesel & Turbo and Wärtsilä. Targeting the slow speed two stroke engines, the key to successful implementation of automatic loop control is reliable sensors able to accurately measure cylinder pressure, providing key data to evaluate the fuel efficiency and engine conditions. Without automatic loop control, ship engines are tuned manually to operate within safe limits while leaving a safety margin for variations in fuel properties and operating conditions. Engines are poorly balanced between cylinders and are often outside recommended deviation limits resulting in increased fuel consumption and higher CO2 emissions. The benefit of auto tuning is that the cylinder pressures are balance and at the highest acceptable pressure offering reduced fuel consumption and CO2 emissions. MAN Diesel & Turbo, ABB, and A.P.Moller have together been running loop control projects since autumn 2007.

Automatic optimization of marine diesel engine performance using loop control of the cylinder pressure process has been under development for a number of years at both MAN Diesel & Turbo and Wärtsilä. Targeting the slow speed two stroke engines, the key to successful implementation of automatic loop control is reliable sensors able to accurately measure cylinder pressure, providing key data to evaluate the fuel efficiency and engine conditions. For every one bar increase in average maximum cylinder firing pressure there is a corresponding decrease of between 0.20 to 0.25 g/kWh in specific fuel consumption

The problem is that without automatic loop control, ship engines are tuned manually to operate within safe limits while leaving a safety margin for variations in fuel properties and operating conditions. Less than 15 per cent of new delivered ships have online cylinder pressure monitoring equipment. According to observations of MAN Diesel & Turbo, engines are poorly balanced between cylinders and are often outside recommended deviation limits. They are also operating with a low maximum cylinder pressure level. The combined  result is an increase in fuel consumption and higher CO2 emissions.

The benefit of auto tuning is that the cylinder pressures are balance and at the highest acceptable pressure offering a potential fuel consumption reduction up to 3 g/kWh with an average of 1 g/kWh and emission potential of 2 per cent CO2 reduction. Additional advantages are  reduced maintenance costs, increased reliability and ease of  workload on the crew.

MAN Diesel & Turbo, ABB, and A.P.Moller have together been running loop control projects since autumn 2007. Under the Danish industry’s Green Ship of the Future project, MAN Diesel & Turbo and A.P.Moller have been field testing an auto tuning system on the MAN B&W 6S60ME-C propulsion engine of the MV Maersk Wizard (present name MV Höegh Kobe) vehicle carrier since early 2008 and the tests continue.

 

Royal Caribbean Stewardship

By Keith Henderson at August 26, 2010 17:46
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The recently issued annual “Stewardship Report” from Royal Caribbean Cruises Ltd includes some detail of its efforts and successes in implementing efficiencies across its fleet of 38 cruise ships. Fuel consumption for 2009 is reduced by 3.7 per cent. The reduction is not absolute but expressed as a ratio to the number of available passenger cruise days (APCD). The saving is partly due to the addition to the fleet of two new ships. These efficiency successes follow a number of years of measuring, testing and deploying a variety of systems including improved hydrodynamics, propeller, propulsion and hull designs. Examples of savings are widespread. Three ships have thin film solar panels on their top decks which provides electricity, on other ships incandescent bulbs are being phased out in favor of LEDs. Many of the ships have the ability to use cold sea water cooling when cruising in the Arctic or Baltic to reduce production of chilled water. Royal Caribbean’s goal for 2010 is to further increase its efficiencies.
The recently issued annual “Stewardship Report” from Royal Caribbean Cruises Ltd includes some detail of its efforts and successes in implementing efficiencies across its fleet of 38 cruise ships. Already achieving an average fuel consumption reduction of 4 per cent in 2008, consumption for 2009 is reduced by a further 3.7 per cent. Not only is this a major cost saving but a proportional reduction of harmful emissions. The reduction is not absolute but expressed as a ratio to the number of available passenger cruise days (APCD).

The saving is partly due to the addition to the fleet of two new ships Celebrity Equinox and Oasis of the Seas. These successes follow a number of years of measuring, testing and deploying a variety of systems including improved hydrodynamics, propeller, propulsion and hull designs. A breakdown of how the consumed fuel was used gives 60 per cent for propulsion including maneuvering, 16 per cent for what is commonly called hotel operations, 11 per cent for heating, ventilation and air conditioning and 13 per cent for engine room and auxiliary equipment.

Examples of savings are widespread. Three ships have thin film solar panels on their top decks which provides electricity to power 7,000 LED lights on two ships and fixed lighting on the Royal Promenade on Oasis of the Seas. On other ships incandescent bulbs are being phased out in favor of LEDs not only to reduce electrical consumption sometimes by as much as 80 per cent - there is a noticeable benefit in the approximate 50 per cent reduction in heat generation with a commensurate lowering of the air conditioning requirement: the LEDs also last much longer and can be recycled.

Many of the ships have the ability to use cold sea water cooling when cruising in the Arctic or Baltic to reduce production of chilled water rendering a saving of between four and five tonnes of fuel daily per ship. Other efficiencies include solar window films to keep the ships cooler, which reduces fuel consumption and associated emissions.

Careful monitoring and adjusting the ship's speed and heading, using inputs of time, wind and current vectors, temperature, and overall sea conditions allows tangible fuel saving to be made. Keeping the ship properly trimmed also saves energy, a system with sensors shows if the ship is listing or out of fore and aft trim and assists in its optimization based on current sea conditions, thereby improving fuel efficiency.

Royal Caribbean’s goal for 2010 is to further increase its efficiencies and save an additional 2.5 percent per APCD and on the subject of greenhouse gase (GHG) in the longer term, it aims to reduce its overall emissions by one third per APCD by 2015, compared to 2008 levels.
 
 

Detonation Gun Engine

By Keith Henderson at August 25, 2010 13:36
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A Canadian physicist and inventor Kazimierz Holubowicz puzzled over the low efficiency of the reciprocating engine operating under normal combustion conditions because he knew that the energy released by fuel exploding, is very much more than under normal combustion. The obvious problem was how to build an engine that would allow fuel to explode (detonate) without the engine exploding! He came up with a design that uses a second free floating piston in a very long cylinder. The free piston oscillates as the main piston is driven downwards turning the crankshaft with the exhaust in the upper cylinder expending most of its energy, harmful SOx and NOx products are dissolved allowing simple treatment and disposal. High torque, low speed and multi fuel capabilities are all attributes claimed for this engine as are low fuel consumption with zero CO and particulate emission. The linear torque vs speed characteristics of this engine make the use of a transmission unnecessary for several applications.
Any engineer will tell you that detonation in an engine is a bad thing and should be avoided otherwise destruction of the engine is a question of time. That’s because abnormal combustion, actually explosion, is taking place inside the combustion chamber and creates pressures about fourteen times normal combustion pressure and a temperature increase that can create hot spots, causing the inlet mixture to pre-ignite, leading to burnt pistons.

A Canadian physicist and inventor Kazimierz Holubowicz puzzled over the low efficiency of the reciprocating engine operating under normal combustion conditions because he knew that the energy released by fuel exploding, is very much more than under normal combustion. The obvious problem was how to build an engine that would allow fuel to explode (detonate) without the engine exploding!

He came up with a design that uses a second free floating piston in a very long cylinder. Basically the detonating fuel in the upper cylinder forces the free piston downward compressing air trapped in the space between the cylinders which act as a cushion. The free piston oscillates as the main piston is driven downwards turning the crankshaft. The exhaust in the upper cylinder expending most of its energy is relatively cool at 140 deg F and steam products of combustion condense to dissolve harmful SOx and NOx products allowing simple treatment and disposal.

The long cylinder and explosion of the mixture somewhat resembles a gun, therefore this engine is sometimes referred to as a gun engine.

High engine torque, low speed and multi fuel capabilities are all attributes claimed for this engine as are low fuel consumption with zero CO and particulate emission. In fact the linear torque vs speed characteristics of this engine make the use of a transmission unnecessary for several applications.

A test engine based on a Suzuki block has shown the principle works in practice along with the other benefits. Recent interest from China in this engine has led to the development of a pre-production prototype model that is already delivering improved results over the original test engine.
 
 
 

Ultrasonic Anti fouling

By Keith Henderson at August 23, 2010 08:23
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The UK Ministry of Defence recently announced that they are going to use ultrasonic anti fouling technology to help maintain the performance of three of its LCVP landing craft, the Australian Customs & Border Protection Service also installed ultrasonic anti fouling equipment on one of its patrol vessels. Several companies producing equipment using the same basic system of transducers attached inside the hull. These vibrations create a strong surface cleaning effect. Algae and slime is broken down and it is the absence of this preliminary surface that prevents marine growth of barnacles, weed etc: all hull materials except wood are suitable for this system. Hull openings such as water jets and tunnel thrusters and appendages e.g. pods and stern drives are also protected. Examples of vessel types for which this system is advertised are trawlers, ferries, tugs, barges and recreational power and sail.
The UK Ministry of Defence recently announced that they are going to use ultrasonic anti fouling technology to help maintain the performance of three of its LCVP landing craft. Each craft is to be fitted with three transducers, protecting not just their hulls but also the stern gear. Earlier this year, the Australian Customs & Border Protection Service also installed ultrasonic anti fouling equipment on one of its vessels tasked to patrol the coast off the country's Northern Territory.

There are several companies producing equipment using the same basic system of transducers attached inside the hull. These vibrations create very small bubbles that adhere to the solid surfaces, the bubbles then implode (cavitation) creating a strong surface cleaning effect. Algae and slime is broken down and it is the absence of this preliminary surface that prevents marine growth of barnacles, weed etc. The manufacturers claim the system is harmless to marine life, and all hull materials except wood are suitable for this system.

The transducers transmit ultrasonic vibrations not only to the hull but also through the water in a 180 degree arc around the transducer. Openings in the hull (water jets, tunnel thrusters) and appendages (pods, stern drives,) are thereby protected even though they are isolated from the hull (though mounts and seals). The number, size and location of the transducers required depends on the vessel configuration and in particular the propulsion gear, location of tunnel thrusters etc.

The transducers are not running all the time but produce the ultrasonic vibrations in pulses of a few seconds at intervals of several minutes. Electricity consumption is low and in small installations can even be run off solar panels. When alongside it is customary to plug into a shore supply to save battery power in the absence of a generator.

Examples of vessel types for which this system is advertised are trawlers, ferries, tugs, barges and recreational power and sail. Protection of the hull alone can be achieved with conventional anti fouling paint but appendages, drives etc are often a major problem, for which ultrasonic anti fouling may offer a solution.

Wind Engine

By Keith Henderson at August 22, 2010 10:09
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In an earlier blog Reducing Air Drag, I mentioned the organization Greenwave. They have another wind power project called the Wind Engine.It is a mechanical sail uses the Magnus Effect and in its practical ship application has a tall cylindrical rotor as pioneered by Flettner in 1926. Test carried out by Auckland University, New Zealand, determined that the thrust produced by the Flettner rotor is eight to ten times more than a sail of equal area. Further tests with a 25:1 model ship indicate that wind assisted propulsion can deliver significant fuel and emission reductions with favorable winds and provides good maneuverability including crash stop performance. Lloyd’s Register provided technical assistance and expertise, for the construction of a full sized prototype rotor that was erected on a site in NE England. The next stage of the project is on board ship tests at sea which will be independently monitored by Lloyd's Register and is scheduled to take place during 2010.
In an earlier blog Reducing Air Drag, I was talking about a wind related project by the UK based shipping environmental charity called Greenwave. They have another project using wind power that is reaching the final development stage and also appears to offer tangible financial benefits to ship owners.

Called the Wind Engine, it is a mechanical sail and is certainly not a new idea. It uses the Magnus Effect to give it its term from Physics and in its practical ship application has a tall cylindrical rotor. Originally pioneered by the German engineer Anton Flettner in 1926., his twin rotor ship the MV Baden Baden completed a transatlantic crossing

Test carried out in this Greenwave project by Auckland University, New Zealand, determined that the thrust produced by the Flettner rotor is eight to ten times more than a sail of equal area. The disadvantage, as with all wind powered vessels is that it doesn’t work if the wind is dead ahead. The equivalent of tacking is achieved by stopping the rotation of the rotor and reversing its direction. Further tests with a 25:1 model ship indicate that wind assisted propulsion can deliver significant fuel and emission reductions with favorable winds. The rotor propulsion also provides good maneuverability including crash stop performance.

The positive results of the model tests encouraged Greenwave to move to a full sized rotor test
Lloyd’s Register provided technical assistance and expertise, for the construction of the full sized prototype rotor measuring 17 m high and diameter 2.3 m. It was erected on a site in NE England by the Port of Blyth where the strong winds make an ideal test site. The results of these full sized rotor tests proved to be even better than the Auckland University wind tunnel tests.

The next stage of the project is the design and construction of two improved Wind Engines to be installed on board a ship for tests at sea. It will use modern materials and manufacturing processes and will be modular to enable containerization for transport to any part of the world for installation locally, under supervision and with appropriate inspection by a classification society.

The sea trial program will be independently monitored by Lloyd's Register and is scheduled to take place during 2010.
               
 
 
 

Reducing Air Drag

By Keith Henderson at August 22, 2010 09:58
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Since 2008, there is a UK based shipping environmental charity called Greenwave that strives to develop policies that not only encourage but reward ship owners for the early adoption of technologies designed to reduce emissions. Their emphasis is on new technical solutions rather than improving existing best practices such as hull and propulsion machinery maintenance, weather routing etc.One of two wind related projects is Turbo-foil, which seeks to reduce the aerodynamic drag of ships. While much attention is devoted to hydrodynamic design, the aerodynamic design, streamlining of ships hasn't changed much over the years with the exception of warships, cruise ships and mega yachts. Tests carried out in the wind tunnel at the University of Auckland has identified where the turbulence is greatest, and where fairing should be mounted to reduce drag. According to Greenwave, practical tests demonstrate that Turbo-foil can reduce above deck drag by at least 20 per cent equivalent to an annual saving of 50 tons of fuel and 150 tons of CO2 production.
Since 2008, there is a UK based shipping environmental charity called Greenwave that strives to develop policies that not only encourage but reward ship owners for the early adoption of technologies designed to reduce emissions. Greenwave’s emphasis is on new technical solutions rather than improving existing best practices such as hull and propulsion machinery maintenance, weather routing etc.

Their objective approach is to use sound engineering principles to research and develop products that work as opposed to pure theoretical research. In the selection of projects it must have a retro fit capability, be sustainable yet recyclable at life end, require no additional crew and last but not least, show a positive return on investment withing three years!

One of two wind related projects currently under investigation, appear to be offering these beneficial results. Turbo-foil, as it is called, seeks to reduce the aerodynamic drag of ships. If you look at automobiles from the 1930's compared to today’s vehicles the difference is obvious and the drag greatly reduced.

Looking to ships, while much attention is devoted to hydrodynamic design, the aerodynamic design, streamlining hasn't changed much over the years with the exception of warships, cruise ships and. Tests carried out in the wind tunnel at the University of Auckland, New Zealand modeling a ship’s superstructure has identified where the turbulence is greatest and tests which kind of fairings and where they should be mounted to be most beneficial in reducing drag.
After special fairings were manufactured the ship’s own engineers where able to mount them within two days providing an immediate benefit.

According to Greenwave, practical tests demonstrate that Turbo-foil can reduce above deck drag by at least 20 per cent equivalent to an annual saving of 50 tons of fuel and 150 tons of CO2 production. For maximum benefit the Turbo Foil aerodynamic drag kit is most appropriate for vessels regularly sailing routes with the wind on the bow.


   
 
 
 
 

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