Wartsila v/s MAN Marine Engines- Who’s is the best ?

                                               

         The stronger the marine engine, the better is the ship’s propulsion power and speed. When it comes to selecting marine engines for ships, there are only a few countable names in the market, including MAN B&W and Wartsila.In this article we are going to compare the two most powerful marine engine brands in the maritime industry.As discussed in one of our previous articles, the Most Popular Marine Propulsion Engines , MAN Diesel Turbo (previously known as MAN B&W) and Wartsila (Previously known as SULZER) are the two front-runner giants for supplying propulsion solution to the shipping industry.Wartsila & MAN both are in fact two rivals who have the best products and R&D in the industry. In this article, we will compare the different propulsion technologies provided by these two companies and will list out which technology has got the edge over the other.Note: This comparison is derived and compiled after taking views from professional marine engineers who have worked on both of these engines. However, this is not a yardstick for selecting marine engines for a ship.

Wartsila v/s MAN Marine Engines

Technology/ System	Wartsila SULZER	MAN Diesel Turbo	Who gets the EDGE?
Intelligent Engine	RT Flex- A complete electronically controlled engine with common rail system	ME Engine- Complete electronically controlled engine integrated with hydraulic control.	Wartsila- For installing an Intelligent engine technology in 2001. Prior to MAN (2003).
Fuel Injection System	Common rail Electronic control with Delta Injection System	Hydraulic actuated Electronic Control Injection system	Wartsila- For integrating Delta control with 3 injectors controlled independently for different load.
Exhaust Valve Control	Electronically controlled variable exhaust valve timing	Camshaft operated Exhaust valve for reliable operation	MAN- For integrating a smart mechanical exhaust valve operation in Intelligent engine for reliable operation.
Fuel Injectors	Conventional fuel injectors	Zero Sac Volume type fuel injectors with slide valve	MAN- Slide type fuel injector reduces after burning and hence NOx emission
Fuel Pump	Spill, suction valve controlled pump with VIT	Jerk type plunger barrel controlled pump with Super VIT	MAN- Super VIT with independent injection timing control w.r.t fuel index.
Starting Air system	Starting air valve opened by 30 bar air and a closing supply for positive shut along with spring. A relief valve in air manifold to avoid overpressure during starting airline explosion.	Starting air valve open by 30 bar air and shut by spring. Bursting disc provided to avoid overpressure during explosion	Wartsila- Additional safety provided in positive closing and relief valve for reliability during manoeuvring.
Piston and Rings	Convex shaped piston with Jet Shaker cooling. Chromium coated Piston ring.	OROS type Piston for better combustion area and reduction in piston temperature. Controlled Pressure Relief type top piston ring.	MAN-With OROS piston, the Maximum piston temperature reduces by 90°C. With CPR ring, better pressure distribution on liner and lower ring.
Cylinder Liner	Fine honed and bore cooled Liner with mid layer insulation.	Bore cooled liner.	Wartsila- Better cooling and insulation increases Cylinder liner Life
Main Bearing	White metal bearing lined on thin back.	Tri metal bearing with high load carrying capacity.	MAN-Tri metal bearing with long life and better embed ability.
Crosshead	12-15 bar pressure from separate pump supplied to bigger size plain bearing.	Small size bearing with oil wedges to retain oil which is supplied by normal system pressure.	Wartsila-Elevated pressure ensures better lubrication at high load. A back up line is provided in case of failure of crosshead pump.
Cylinder Lubrication	Electronically controlled Pulse Lubrication System with metered quantity injection	Alpha Adaptive Cylinder Lubrication control system allowing blending of cylinder oil for different grade of sulphur in fuel	MAN- ACC with different inputs like sulphur content and load index provide better neutralizing features.
Drive	Gear driven with timing gear driving the camshaft	Chain driven with 2 chains driving a camshaft	MAN- Chain drives are cheaper, lighter and easier to maintain and duplication provides backup.
Turbocharging	Prefers Axial turbocharger with constant pulse system.	Variable Turbine Angle turbocharger provides better operation at all load range	MAN-VTA allows engine to run without auxiliary blower at low load operation.
Exhaust Valve	Cobentional Valve seat with Nimonic and Stellite coating	W seat for better operation and increased time between overhaul. Dura spindle with better heat resistant property.	MAN- W seat allows cooling of exhaust valve during combustion stroke
Miscellaneous	Tribo pack allows increased time between overhaul of cylinder component up to 3 years. Electronic monitoring system for safe operation	Electronic monitoring system for safe operation.	Wartsila- With Tribo pack which is a package of design measures increases the TBO to 3 years.

 From the above comparison, it can be seen that MAN has 

an edges over Wartsila by a thin margins.

However, with the world’s most powerful marine engine (Wärtsilä RT-flex96C) in its basket, Wartsila is one company that doesn’t have to prove anything. 

Dear readers its just an study made under certain cases so there may be any tentative results......for more articles subscribe to my post.......

Ball piston engine - a high efficient power
                Ball piston engine

              The original concept was introduced in 1990. Then it utilised a modified version of the tried and tested otto cycle. The number of strokes were 4, 8 and 12 or more. There may be one or more pistons. Each of them is inside a cylinder. A hot gas or a gas under pressure is introduced. The machine design concept is applicable as a compressor, pump, motor, or engine. This engine is based on spherical ball pistons and hence the moving part count is less, power to weight ratio is high, f valve train and water cooling systems are eliminated and there is a good dynamic balance.
 The inertial loads(which contributes to sliding friction) has been completely eliminated by a novel kinematic design. a small clearance is kept on the ball piston to avoid the use of piston rings for reducing the leakage. As a result, there is a choked flow across the piston. The above described features provide the scope for a engine with higher efficiency than conventional piston engines.The silicon nitride ball pistons technology has been utilized by the engine preventing the need of a large developmental effort.

Ball piston engine - a high efficient power

                A patented new power machine concept has been designed and analyzed for production, and proof of principle subscale tests have been performed, with positive results. The machine design concept is applicable as a compressor, pump, motor, or engine. Simplicity of design based on spherical ball pistons enables a low moving part count, high power to weight ratio, elimination of valve train and water cooling systems, and perfect dynamic balance.The new design concept utilizes novel kinematic design to completely eliminate inertial loads that would contribute to sliding friction. Also low leakage is maintained without piston rings by using a small clearance on the ball piston, resulting in choked flow past the ball. These features provide the potential for an engine with higher efficiency than conventional piston engines. The engine design utilizes existing recent technology to advantage, such as silicon nitride ball pistons, so a large development effort is not required.  

The further more information can be read from the following links......keep reading the blogs....

http://papers.sae.org/970066/

http://www.ballpistonengine.com/

http://www.convergence-eng.com/project_f...esting.doc

for a presentation, visit this link:

http://www.scribd.com/doc/11835319/Ball-Piston

http://www.scribd.com/doc/29379090/The-B...ton-Engine

Reference: http://www.seminarprojects.com/Thread-ball-piston-engine-a-high-efficient-power?pid=19342#pid19342#ixzz0w1qOFneT

Reference: http://www.seminarprojects.com/Thread-ball-piston-engine-a-high-efficient-power?pid=19342#pid19342#ixzz0w1qgJvRb

Free Piston Engine

                The Free Piston Engine is a combination of reciprocating engine and rotary turbine. It is called free piston engine because the freedom motion for Mechanical linkage which gives variable stroke according to load.

 ADVANTAGES
 1. Mechanical simplicity
2. Less power to weight ratio
3. Lower turbine operating tempeatures
4. Multi fuel capability
5. Flexibility and reliability
6. Easy starting and control

LIMITATIONS

1. Poor fuel economic
2. Less stability
3. Poor part load efficiency
4. High combustine rates
5. Reduction gearing

  APPLICATIONS
 1. Free piston engines are widely used as submarine air compressor units
2. These engines are suitable for power generation in medium power range
3. Free piston engine have been tride in ship propulsion, road and rail traction and even in aircrafts.
4. It is used in mixed gas steam cycle