Marine diesel engine

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Cylinder head of the eight - cylinder two-stroke diesel engine from MAN B&W (now MAN Energy Solutions ) on the VLCC Algarve
Crankcase of the MAN B&W diesel engine on the VLCC Algarve
Yanmar 2GM20 20 hp two-cylinder diesel engine in a sailing boat

A ship's diesel engine is a diesel engine that serves as the main or auxiliary engine on a ship. Motors of the same or similar construction are also used stationary in power plants on islands and other remote locations, and operated as emergency power generators, for example in hospitals, major banks, data centers and nuclear power plants .

Four-stroke diesel engines are also used for small ships or boats; Today their characteristics are more like the engines of commercial vehicles in rural areas.

Ship diesel engines can be operated with diesel fuel , gas oil , heavy oil (HFO) or, for some time now, with gas . Orimulsion was also used as a fuel until the end of 2006 . The term diesel refers to the work process, which, according to the definition, is characterized by the intake of air, its compression with accompanying heating and auto-ignition after the fuel has been injected.

conditions

  • The requirements for operational safety and reliability are significantly higher than for stationary diesel engines or those used in land vehicles. If the propulsion of a ship fails and it stops moving, the rudder is no longer flowed against. This makes the ship almost completely incapable of maneuvering. In heavy seas, the ship can lay sideways and may get into distress. There are high costs for salvage and spoiled / delayed cargo up to the total loss of the ship.
  • There is great value to a long life down to long-term operational costs ( Engl. Total Cost of Ownership ) to be minimized. In addition, repairs or even the replacement of the machine are associated with considerable effort, such as the dismantling of superstructures, the opening of decks above or the ship's side. This in turn leads to long docking times during which the ship is not available.
  • A seagoing ship must be able to provide a high level of continuous output, that is, be able to survive long distances at full speed.
  • Low fuel consumption is important because the rise in crude oil prices has also caused heavy fuel oil prices to rise significantly. Today's marine diesel engines achieve specific consumption levels of less than 180 g / kWh.
  • A trend towards “dual fuel engines” (diesel and natural gas) can be observed, as natural gas tends to be cheaper than HFO . However, dual-fuel engines never achieve such favorable consumption values ​​as single-fuel engines.
  • A high degree of automation is state of the art today. Ship engines are increasingly being operated in guard-free mode, so that alarms and other events must be processed electronically and transmitted to the officer on watch or the machinist in a suitable manner. In the event of danger, the machine switches off automatically or reduces the load. However, alarms and stops can also be ignored if the situation requires it (ship in front of engine / override). In addition, ship engine systems are usually black-start capable , whereby at least one diesel generator can also be started completely manually in an emergency, so that auxiliary energy is then also available again to operate the main engine.
  • In inboard engines of boats, especially sailing boats, today diesel engines are used almost exclusively, even with very low power, because diesel fuel, unlike motor gasoline, does not form toxic vapors that can be distributed in the hull and pose a risk of explosion when started. Engine compartments of ships with gasoline engines have to be equipped with ventilation fans, which must also be started before the engine is started. These regulations do not apply to diesel engines, which means that they are ready to start at any time, apart from a short pre-glow.

Types

Crankshaft of a low-speed two-stroke engine

Depending on the size of the ship and the type of propulsion, various types of diesel engines are used. They are equipped with an exhaust gas turbocharger and intercooler.

  • Medium-speed 4-stroke diesel engines with a speed range of up to 1200 revolutions per minute are primarily installed on small to medium-sized cargo ships, passenger ships and warships . Depending on the size, they are designed as in- line or V-engines with up to 20 cylinders, the bore up to 640 mm, piston speed up to 11 m / s and a cylinder output between 100 and 2150 kW. Large four-stroke diesel engines achieve specific consumption levels of less than 180 g / kWh. These motors require a gear reduction or drive generators for a diesel-electric drive, which is also designed as a pod drive on cruise ships , often in conjunction with controllable pitch propellers or water jet propulsion . Another important use of supercharged diesel engines of this type is the generation of electricity on board. For this purpose, so-called auxiliary diesels drive a generator at constant speed . (E.g .: 1800 revolutions per minute motor speed in a four-pole generator produce 60 Hz alternating current).
  • High-speed runners, the speed of which can exceed 2000 revolutions per minute, can be found in the area of ​​inland waterways and in sport and leisure shipping.
Section through an exhaust gas turbocharger for an auxiliary diesel

Other sources mention other speed ranges (up to 400 / min; 400–1000 / min; over 1000 / min).

Construction methods

Single-cylinder marine diesel
  • The engines are differentiated according to their working principle and the arrangement of their cylinders. Two-stroke engines are built as in-line and V-engines (except as opposed piston engines e.g. from Napier Deltic ), V-engines from Detroit Diesel.
  • Large marine propulsion diesel engines are usually slow-running 2- stroke crosshead engines that are built as in-line engines with 5 to 14 cylinders. Large 2-stroke crosshead engines have heated fuel lines and appropriately equipped injectors and pumps and with heavy fuel oil (HFO from English. Heavy fuel oil operated). Older engines were started up with diesel fuel and only switched to heavy fuel oil on the open sea. Slow runners usually work directly on the propeller shaft. The direction of rotation of the machine can be reversed, for which the motor must be stopped. To start the engine backwards, either the camshaft is shifted hydraulically or pneumatically, or the tappet rollers are placed on the other flank of the injection pump cam and the engine is restarted. State-of-the-art large diesels are partially designed without a camshaft, so that the reversing process in this form is not necessary.
  • In- line engines with up to 14 cylinders are used as the main engine in large container ships , ore freighters and oil tankers, with bores up to 1.08 m and strokes up to 3.10 m, the continuous output of which is sometimes up to 100 MW ( MAN Diesel 14K108ME-C) . Such an engine is 32.65 m long, 13.80 m high and has a weight of 2828 tons. The oil filling is several 10,000 liters. These marine diesel engines are equipped with turbocharging to increase efficiency and specific power. You can achieve a service life of over 20 years, i.e. around 150,000 operating hours.
  • Four-stroke engines have also been able to run on heavy fuel for some time, but then require a gearbox in the drive train, as the propeller requires a significantly lower speed. There are four-stroke engines as in-line and V-engines as well as in some exotic arrangements, such as. B. radial engines (six stars with seven cylinders each in a row) for speedboats.
  • Although most outboard motors are designed as gasoline engines, there are also occasional diesel units, especially in the area of ​​commercially used outboard motors. In the 1990s, for example, Yanmar built outboard diesel engines with 27 and 36 hp. Currently one of the few suppliers of outboard diesel engines is the German Neander Motors AG.

Gas-powered four-stroke engines are interesting for stationary applications and also for LNG tankers. For some time now, several engine manufacturers have been offering so-called DF engines (dual fuel). So far as four-stroke engines, but a two-stroke engine will also come onto the market in the foreseeable future. The gas is ignited by means of a pilot injection with diesel fuel . The share of diesel fuel in the combustion process is only about 1%, the remaining energy is obtained from gas. The engine is also able to burn diesel fuel as the main fuel. This method has the advantage that the gas tanker can be operated with the boiled off gas during the cargo voyage (the portion of the liquefied gas that evaporates during transport) and with diesel fuel during the ballast voyage. Triple fuel engines are under development; these engines are also able to burn heavy fuel oil.

In-line engine

Twelve-cylinder V-engine in a barge

Link rod of a V8 aircraft engine (Renault 8Gd from 1917)

In-line engine is the name for engines whose cylinders are arranged in a row. The counting (designation) of the cylinders in marine diesel engines begins on the power-emitting (flywheel) side.

V engine

The cylinders or cylinder banks in the V-engine are inclined between 15 ° and 90 °, but usually 40-60 ° to each other (depending on the number of cylinders) and - if both connecting rods work directly on the same crank pin - are arranged somewhat offset.

In V-engines, the connecting rods of the cylinder pairs that belong together can be articulated to the same crankshaft throat or to different throws rotated against each other around the crankshaft center . Occasionally only one drive rod of the cylinder pair engages directly on the crank pin, the slightly shorter drive rod of the second cylinder is hinged to the other (connecting rod).

To designate the cylinders, the cylinder row on the left as seen from the clutch side is designated as the A-side, the other as the B-side. The numbering of the cylinders in German marine diesel engines begins on the power-emitting (flywheel) side.

Technical data of selected marine diesel engines

Manufacturer Type Type of construction Bore (mm) Stroke (mm) Cubic capacity / cyl. (Liter) Power / cyl. (kW) Speed ​​(1 / min) Medium piston size (m / s) use as Application examples
MAN B&W K98ME-C6 980 2,660 2,006.4 5,720 94 8.3 Container ships
Wärtsilä - Sulzer RT-flex96C 960 2,500 1,809.6 5,720 102 8.5 Container ships
Wärtsilä - Sulzer RTA84T 840 3,150 1,745.7 4,200 76 8.0 Tankers and cargo ships
Wärtsilä 64 640 900 289.5 2.010 333 10.0 Cargo and cruise ships
MAN B&W 58/64 580 640 169.1 1,400 428 9.1 Cargo and cruise ships
Wärtsilä 46 460 580 96.4 1,050 514 9.9 Cargo and cruise ships
MaK M43C 430 610 88.6 1,000 500 10.2 Cargo and cruise ships
Sulzer ZA40S 400 560 70.4 720 510 9.5 Cargo and cruise ships
Caterpillar C280 280 300 18.5 339 1,000 10.0 Cargo and passenger ships
MTU 8000 series 265 315 17.4 455 1,150 12.1 Passenger ships, tugs
ABC DZC 256 310 16 221 1,000 10.3 Coastal and inland waterway vessels, tugs
Yanmar Marine 1GM10
  • 4-stroke with indirect injection
  • fast running
  • 1 cylinder with flywheel
 75 72 0.318 6.7 3600 8.6 Sailing ships up to approx. 10 m in length

Power transmission

There are mainly three different ways of transmitting power from the engine to the propeller .

Directly

Shaft in the shaft tunnel (from the main engine to the propeller)

A shaft that is rigidly connected to the motor and propeller is driven. The direction of rotation of the propeller can, for. B. for reversing, can only be changed here by reversing the motor. The engine must then be stopped while driving ahead, reversed by shifting the camshaft, and restarted for reversing. This method is used in all cases with a rigid connection between propeller and motor.

Another possibility is the controllable pitch propeller . For changing the speed of the ship and for the advance or back direction, the individual propeller blade in a different angle (slope, engl. Pitch ) is rotated (turned on). The motor rotates at a constant speed. This speed can be higher than that suitable for the propeller. Therefore, in such a case, the speed must be reduced via a gear unit. In addition to diameter and pitch, cavitation also plays a decisive role in the speed of the propeller . Cavitation is the collapse (imploding) of gas bubbles, which can damage the surfaces of the propeller blades.

Diesel mechanically

Particularly used in high- and medium-speed engines that require a reduction in engine speed to propeller speed. The gearboxes used are partly equipped with switchable clutches and power take-offs for shaft generators . Reversing gears are used to reverse the direction of rotation of the propeller in non-reversible motors. There are also combinations of gearboxes and controllable pitch propellers . Often the ship's engines are flanged to the gearbox via couplings (e.g. of the Vulkan Rato type ) or link joint disks . This avoids the vibrations that occur with conventional metal connections. The drive is decoupled.

In the case of small engines, reversing gear and speed are often operated using a simple mechanism using a single-lever switch . The reversing gear can be simply built here, since switching can only take place in idle.

Diesel-electric

With diesel-electric drives , the engine, usually a 4-stroke engine, only drives a generator that provides the power for the traction motor, which in turn drives the propeller . This variant is particularly common as a multi-engine system on passenger ships . The individual generator units can be installed anywhere on the ship. They also generate energy for hotel operations, which makes up a significant proportion of the total energy requirement for passenger ships. Individual generators can be switched off and switched on, maintenance and repair of a machine is possible while the ship is in operation at sea. The direction and speed of rotation of the propeller are independent of the speed of the internal combustion engines, so that the internal combustion engines can be operated in the working areas of the highest efficiency. Because of the losses in the generation and conversion of electrical energy, the overall efficiency is somewhat worse than with a direct drive.

Example Queen Elizabeth 2 ( Cunard Line ): In the 1980s, converted from steam turbine drive to diesel operation. Nine machines MAN 9L58 / 64 ([Line] 580 mm bore 9-cylinder in-line, 640 mm stroke) with about 1200 kW per cylinder working on generators on two 44 MW payable GEC - traction motors with two propellers. In addition to the widespread controllable pitch propeller systems, a special form of this drive is the newly developed pod drive .

Clear up and settle down

Historic two-stroke marine diesel engine 40 DM with controllable pitch propeller system and an output of 1620 kW (2200 PS)

This section describes the work necessary to start and stop a large 2-stroke marine engine.

  • When the machine is at a standstill, it is usually kept at a constant lower operating temperature by the high temperature (HT) cooling water system and a preheating pump.

The heavy fuel oil temperatures in the day tanks must be checked before starting . When the main engine is at a standstill, the thermal oil or the steam, which circulates in pipes in the tanks to keep the heavy oil at its temperature, is heated by a boiler operated with diesel oil and not, as during operation, by the exhaust gas temperature in the chimney (exhaust gas boiler).

Ship diesels are started using compressed air. An electric motor could not generate the required power with a reasonable size ratio.

The compressed air cylinders and the starting air system are drained and the pressures are checked.

Just like the preheating pump, the fuel system also works continuously to maintain the temperature of the heavy fuel oil in the supply and discharge lines (ring line) to the machine. Cooling the heavy oil in these areas would lead to clumping. The pipelines would have to be cleaned at great expense. It may be necessary to operate the machine with gas oil for a certain period of time.

Smaller engines can be equipped with a (attached) lubricating oil pump which is coupled to the engine and which runs during operation and thus supplies the bearings of the main engine with lubricating oil. When the main engine is at a standstill, the oil pressure must then be maintained via an external, electrically operated pump, also to ensure that the machine is relubricated accordingly after it is stopped. Cooling water pumps can also be attached. Before starting, the system must be subjected to a visual inspection and the lubricating oil pressure must be checked.

In order to be able to drive the machine out of the engine control room (MKR) in an emergency or if the remote control from the bridge fails, all communication devices such as the engine telegraph and telephone (connection bridge to MKR and bridge to the steering gear room) must be functional. The machine has an emergency control station directly on the engine. Should the propeller blade adjustment device fail on a ship with a controllable pitch propeller, it could be manually moved to 100 percent position and the speed of the ship regulated via the engine speed. If not yet in operation, a second auxiliary diesel is started from the MKR and synchronized with the network in order to avoid the first and then only auxiliary diesel being thrown off after the numerous pumps (consumers with high energy requirements) have been switched on automatically (power failure).

The necessary pumps are started or switched to automatic mode via the control panels in the machine control room. These essentially include:

  • Sea cooling water pump
  • HT cooling water pump (high temperature)
  • LT cooling water pump (low temperature, low temperature. Sea water cools the LT circuit, LT cools HT, HT cools the machine. These staggered cooling circuits are intended to protect the motor from stress cracks by means of lower temperature differences)
  • Transmission oil pump
  • Lubricating oil pump
  • For two-stroke engines: scavenging air pumps
  • On ships with controllable pitch propellers: control oil pump

This is followed by the activation of the alarms suppressed in port operation, such as oil pressure and temperature, HT and LT cooling water temperature.

At the machine's emergency drive, the shut-off valve for starting air is opened manually and the filling linkage (fuel quantity) is released for automatic operation. The control is then switched from the emergency control station to the control room.

After opening the decompression valves, the engine is blown through with starting air. Any water, oil or fuel in the piston chamber is expelled from the valves. If a machine is started with water in the piston chamber, this can cause serious damage to the engine. The decompression valves are then closed again.

Check the main engine for cooling water and oil leaks.

  • Screw connections are attached to the decompression valves in order to be able to record the pressure profile per work cycle with a writing instrument. In this way, information about the combustion process of the relevant cylinder can be obtained during operation.

Startup process

Starting air compressors on board a ship

The automated starting process of the main engine is initiated from the MKR.

To start a large diesel, the large component masses must first be set in motion and the power-consuming work steps within the engine must be overcome (intake, compression, work, ejection). For large ship engines, this work can no longer be done by an electric or air motor.

Marine diesel engines are therefore always started with compressed air. In the case of smaller units below 10 MW, compressed air starters are also occasionally used, which attack the flywheel and thus spin the machine. Large four-stroke engines and practically all two-stroke engines are started directly. Each cylinder is supplied with starting air according to its position and the ignition sequence. The corresponding pistons are pressed down one after the other and the engine speed is increased to ignition speed. The controller sets the injection pumps to filling, fuel is injected and the first auto-ignition occurs . This requires a strong compressed air system (usually 30 bar nominal pressure).

In order to expel the combustion gases in large, slow-running two-stroke diesel engines and to supply fresh air, electrically operated purge air fans are used in the low load range. In the higher load ranges, exhaust-driven turbochargers take over the task.

In order to ensure operational safety, marine diesel engines, in particular the auxiliary machine for generating electricity, can be started even after failure of the entire electrical energy supply on board ( blackout ) by manually operated start valves and without ancillary units, as long as there is sufficient compressed air in the starting air pressure tank and fuel in the day tanks is available.

All travel commands coming from the bridge are carried out from the engine control room. Above all, this includes turning the engine around during maneuvers (in order to move a ship astern, the main engine must be stopped and completely restarted in the other direction).

In the case of a ship with a controllable pitch propeller, the engine is slowly ramped up to its nominal speed. In this state, the machine is left idling for a few minutes in order to stabilize temperatures and pressures. After increasing to constant speed, the control of the machine is transferred to the bridge (remote control) and accepted and accepted from there at the push of a button.

Thanks to the constant speed at sea, the power supply can be taken over by a shaft generator driven by the main engine instead of separate harbor or auxiliary diesel generators.

Ships without controllable pitch propellers only accelerate very slowly. The reason is the angle of attack of the propeller, which is only optimized for one speed. If the propeller is operated at too high a speed at too slow a speed, excessive cavitation can occur, which significantly impairs the propeller efficiency.

Drop

The auxiliary diesel engines are started at the end of the voyage and, after synchronization with the wave generator, are switched on to take over the power supply.

After the end of the voyage or the mooring of the ship, the bridge transfers control of the engine back to the MKR, which in turn has to be acknowledged from there.

On ships with controllable pitch propellers, the engine is then reduced from constant speed to idle speed. In this state, the machine continues to run for a few minutes in order to cool down slowly and avoid stress cracks. The machine control is switched to the emergency control station. From there the filling linkage is set to stop, the valve for the starting air supply is closed and the indicator valves are opened.

After a few minutes of relubrication, the electric prelubrication pump is switched off.

The cooling water circuits are set to port operation and the electric preheating pump is put into operation. The alarms that are not required for port operations, such as oil pressure, HT and LT cooling water temperature, are now suppressed.

business

A number of special additional systems are required to operate and start a ship's diesel. If one of these systems fails, the main machine must also be stopped. That is why there are a number of auxiliary units in duplicate : lubricating oil pumps, fuel booster pumps, cooling water pumps, lubricating oil separators , compressors, fuel and lubricating oil filters.

Lubricating oil system

As with other internal combustion engines , these parts are well lubricated to minimize wear and tear on rubbing surfaces inside the machine .

The lubricating oil essentially takes on four tasks:

After the oil has been pumped out of the oil pan or the circulation tank and cleaned through a filter, it passes through an oil cooler . Then the various lubricating oil lines branch off to the crankshaft, connecting rod bearings and into the oil pan. Another small part is used to lubricate the camshaft , rocker arms , valves and to cool the pistons. The oil runs back into the oil pan or the circulation tank. The pistons are lubricated by a separate oil system.

In case of insufficient amount of oil in circulation tank may under heavy list to come that the suction port of the oil pump does not reach the oil level so that the lubrication is interrupted. Separators are used to prepare and heat the circulating lubricating oil.

Fuel processing

On seagoing vessels, i. d. As a rule, low-quality heavy fuel oil ( H eavy F uel O il (HFO)) is used as fuel, which is obtained as residual oil during petroleum refining . In the storage tanks, which are usually arranged in the double bottoms of the ships, the fuel is heated to at least 40 ° C so that it remains pumpable and can then be transported into the engine compartment tanks. In so-called settling tanks, which are heated to approx. 70 ° C, some of the water and sludge are already deposited on the fuel. Water and mud are regularly drained into mud tanks. The fuel is then further processed by separating and filtering it.

Mineral oil separators are centrifuges in which a gear pump pushes the oil at high pressure through a stack of stainless steel plates rotating at high speed (12,000 / min). The conically shaped plates are equipped with riser channels through which the pure and therefore lighter oil rises, while heavy components such as water and dirt are diverted to the outside due to centrifugal force and are collected in the drum ( material separation ). The dividing line between the light and heavy phase should run in the first third of the riser channels. A distinction is made between clarifiers , which only separate dirt, and purifiers , which essentially separate water and sludge. A key distinguishing feature of these two types is the closed closing plate in the riser duct in the case of the clarifier or the adjustable so-called water disc in the case of the purifier.

Separate fuel heat exchangers are connected upstream of the separators. Depending on the fuel density, the separation temperatures must be between 70 and 99 ° C. In the case of heavy oils with a high proportion of pollution, the separator types are also connected in series. The sludge drum is emptied by applying water pressure to the piston valve, which releases the emptying openings in the drum so that the heavy contaminants can be thrown out and collected in the sludge tank. Regular emptying of the separators can be done automatically or manually. The heavy oil separators are sensitive components that are important for safe engine operation and that have to be checked regularly for their function.

The fuel filters are mostly so-called backwash filters . With a certain degree of contamination of the sieve surfaces - whereby a differential pressure is measured - fresh oil is pressed from backwards through the sieve surfaces by diverting the fuel flow and thus the dirt is flushed into a dirt tank. The separated and filtered fuel is provided in so-called day tanks for the engines. The day tanks are equipped with a fuel overflow to the settling tanks so that continuous cleaning and heating can take place when the separators are in constant operation.

The HFO fuel is preheated to injection viscosity (approx. 12  cSt at approx. 130 ° C) in a viscosity- controlled manner in separate modules, and the pressure is increased to around 7 to 10 bar. Before entering the engine's fuel injection pumps, the fuel is passed through a final fine filter. When operating with lighter diesel oil, a fuel cooler is provided in the partial load range.

To supply the fuel injection pumps when operating with heavy oil of high viscosity classes, the fuel is first pumped into a collecting vessel by means of feed pumps at a pressure of around 6 to 8 bar. So-called booster pumps convey the fuel to the fuel injection pumps from this collecting vessel when the pressure increases to around 15 to 18 bar. The pressure increase is necessary to prevent the harmful partial evaporation of the fuel, which has been heated to approximately 130 to 140 ° C., in the fuel injection pumps during shutdown. The fuel inlet and outlet are routed through the pump housing and the ram guide of the fuel injection pumps. The principle of the fuel pump control is based on the bevel control developed by Bosch. The pump piston ( plunger ) is moved vertically in the piston guide (English barrel ) by the fuel cam of the camshaft and overlaps the fuel inlet and outlet bores. For this purpose, a recess with a sloping, sharp edge is milled vertically into the punch body. The pump ram can be rotated around its axis depending on the load or speed. The inclined edge (control edge) allows the return of fuel into the drain hole and thus the volume of fuel to be injected into the combustion chamber to be controlled. In order to avoid the retarded ignition that occurs during partial load operation, the punch guides are automatically, pneumatically / hydraulically adjusted ( variable injection timing , VIT). The fuel injection pumps deliver the fuel to the fuel injection valves under high pressure (approx. 900 to 1600 bar). A strong, adjustable spring is built into the injector bodies. This spring presses the seat of the valve needle onto the inlet bore of the nozzle via a spindle. Several fine, sharp-edged holes are machined into the nozzle. The fuel is fed through a channel machined into the valve body to under the needle seat. The pump pressure initially lifts the needle seat from the nozzle inlet against the spring pressure, so that the fuel enters the combustion chamber. After that, the spring pressure prevails again, which allows the needle seat to close the nozzle inlet. This process is repeated several times in quick succession during the injection process, which means that the fuel is finely atomized and reaches the combustion chamber.

Efforts are under way to replace this injection technology with common rail technology . Common rail technology is now ready for series production at many marine diesel engine manufacturers.

Cooling circuit

The heat that is generated in the machine during combustion must be dissipated to the outside. The cooling water should have a temperature of 80 to 90 ° C at the outlet in order to avoid stress cracks, which can arise from excessive temperature differences between components and the large dimensions of a ship's diesel engine. Cooling water with an inlet temperature of around 70 ° C is passed from bottom to top through the components to be cooled. The cooling water is directed from the water jacket of the liner cooling through the cylinder heads, the exhaust valves and the turbocharger .

Most marine engines have at least two cooling water circuits:

  • A circuit that carries fresh water that enters the lower part of the machine, is pumped to the cylinder heads and exits the machine there. This fresh water is cooled
    • either via a fresh water low-temperature cooling water circuit, which also cools the oil and charge air cooler , among other things , or
    • a cooling circuit that uses seawater. This prevents the seawater from coming into direct contact with the machine, which would lead to considerable corrosion . If the ship has a low-temperature cooling circuit, this is cooled by the sea cooling water. In between, a heat exchanger takes care of the heat transport.

Very small marine engines like the 1GM10 mentioned above are cooled directly with seawater despite the risk of corrosion. This saves the effort for a second cooling circuit with a separate pump and corresponding expansion tanks.

Environmental aspects

Large parts of world trade are carried out by ship. In order to reduce further pollution of the oceans and the air, lower exhaust gas emissions are increasingly required. As a result of the new guidelines issued by the International Maritime Organization (IMO, an organization of the United Nations ), stricter limit values ​​for the emission of certain pollutants must be observed in the future (including in particular nitrogen oxides , which are increasingly formed during slow, high-temperature combustion.) In addition, there is an indirect limitation of sulfur dioxide emissions due to the new limits on the sulfur content in the fuel. On July 15, 2011, the EU Commission published a “Proposal for a directive of the European Parliament and the Council to amend Directive 1999/32 / EC with regard to the sulfur content of marine fuels”. The Shippingefficiency database, founded on the initiative of the British entrepreneur Richard Branson , compares different ships of one type with one another; The aim is for ports to stagger their fees according to the pollutant emissions in the future.

In order to avoid increased pollutant emissions and low efficiency at low speeds, modern inland waterway vessels rely on a father-and-son engine concept: if the ship is fully loaded upstream, the large ship's engines work. Smaller engines run instead when traveling downhill and canal - but sometimes even upstream unloaded. Such systems are since 2012 on the axis group "El Niño / La Niña" and since 2015 on the axis group "Rhenus Duisburg" in use.

Exhaust gas cleaning is technically feasible today with catalytic converters and particle filters and is also mandatory; However, the more than 20 year old marine diesel engines, which make up the majority, are harmful to the environment and their exhaust gases are not yet cleaned, mainly for cost reasons. The limit values ​​for nitrogen oxides are often exceeded, and sulfur oxides and fine dust are also released.

Manufacturer

Slow runner (speed 75–200 1 / min):

Medium speed (speed 500–1000 rpm):

Fast runner (speed 1000-3000 rpm):

Outboard diesel engines:

  • Neander Motors AG

See also

literature

  • Wolfgang Kalide: Piston and flow machines. 1st edition, Carl-Hanser-Verlag, Munich Vienna 1974, ISBN 3-446-11752-0
  • Richard van Basshuysen, Fred Schäfer: Handbook Internal Combustion Engine: Fundamentals, Components, Systems, Perspectives. 3rd edition, Friedrich Vieweg & Sohn Verlag / GWV Fachverlage GmbH, Wiesbaden 2005, ISBN 3-528-23933-6 .
  • Hans-Jürgen Reuß: Two-stroke engine program geared entirely to gas. MAN Diesel & Turbo is demonstrating a new engine with alternating operation from diesel to gas in Copenhagen. In: Hansa , Heft 7/2011, pp. 43-44, Schiffahrts-Verlag Hansa, Hamburg 2011, ISSN  0017-7504
  • Detlev Sakautzky: Ship engine operation: basic knowledge - learning aid. Pro Business, 2009, ISBN 978-3-86805-348-7 .

Individual evidence

  1. ↑ a b http://www.triple-x-marine.com/ : Explanations on overspeed in marine diesel engines  ( page can no longer be accessed , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. .@1@ 2Template: Dead Link / www.triple-x-marine.com  
  2. ↑ BOOTE magazine: Tubodiesel outboard: Neander Shark. Retrieved October 1, 2018 .
  3. ↑ MAN B&W K98ME-C6 Project Guide , accessed October 24, 2014
  4. ↑ a b Wärtsilä Low Speed ​​Engines , accessed on March 19, 2010.
  5. ↑ a b Wärtsilä Medium Speed ​​Engines , accessed on March 19, 2010.
  6. ^ MAN Medium Speed ​​Engines , accessed on March 19, 2010.
  7. ↑ a b Cat and MaK Propulsion Engines , accessed March 19, 2010.
  8. ↑ The Medium Speed ​​4 Stroke Trunk Piston Engine , accessed October 17, 2010.
  9. ↑ MTU - Diesel Engines for Passenger Ships and Ferries ( Memento of the original from July 21, 2013 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , accessed March 11, 2011. @1@ 2Template: Webachiv / IABot / www.mtu-online.com
  10. ↑ http://www.abcdiesel.be/Deutsch/Datasheet_DZ_home.htm ( Memento from June 11, 2008 in the Internet Archive ) , accessed on October 6, 2012.
  11. ↑ http://www.abcdiesel.be/Deutsch/Datasheet_V-DZC_home.htm ( Memento from June 9, 2008 in the Internet Archive ) , accessed on October 6, 2012.
  12. ↑ Yanmar 1GM10 . Archived from the original on April 23, 2012. Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved April 22, 2012. @1@ 2Template: Webachiv / IABot / www.yanmarmarine.com
  13. ↑ see also Cleanest Ship
  14. ↑ DIRECTIVE OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL amending Directive 1999/32 / EC with regard to the sulfur content of marine fuels on ec.europa.eu PDF.
  15. ↑ Experience report: Four-engine drive brings 20 percent fuel savings for El Niño on the industry news portal bonapart.de, accessed on September 8, 2015.
  16. ↑ "Rhenus Duisburg" runs with a flex tunnel and four motors on the industry news portal bonapart.de, accessed on September 8, 2015.
  17. ↑ Marlene Weiss: Thick air over the water. Compared to many marine engines, diesel vehicles are virtually clean on the road. Heavy oil is burned on the high seas, while particle filters and catalytic converters are unusual on rivers such as the Rhine . Tages-Anzeiger , Tamedia , Zurich August 16, 2017, p. 36.