Marine diesel engines and repair.

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Marine diesel engines are the source of energy that drives the ship.Rotation of the crankshaft is transmitted to the transmission consisting of the gear mechanism, and integrated rampart bladed propeller, which gives the course of the ship.The larger the ship, the more developed should be its energy system, which should ensure the safety of the vessel at sea.In case of refusal of the main engine is switched backup, as it stops the huge container ship or bulk carrier mnogopalubnogo middle of the ocean in storm conditions equivalent to its destruction.

first swallow

Marine diesel engines began in the early HHveka and immediately declared itself as a reliable, efficient and, most importantly, compact units.The first ship with a diesel engine was the Danish "Zealand", launched in 1912.The vessel was installed two engines at 200 hp.c., each of which is driven by a propeller.The appearance of the vessel with an unusual engine created a furor and became the beginning of a new era of diesel power plants.

Development of power plants on diesel fleet began a rapid pace after the Second World War.The prospect of further use unpretentious propulsion was evident, and many engineering companies throughout the world engaged in their production.As is usually the case, the development of large-scale industrial production of any products which are in high demand, the competition began.As a result, there were unique projects in the course of which were created by powerful superreliable marine engines.

layout

Energy diesel engine plant on a large board consists of one main engine and several auxiliary who work on life support ship.This generators, pumps, ventilation, compressors and many other mechanisms.

On very large ocean liners can be installed several main engines and a plurality of auxiliary.All diesel engines.They serve a team of mechanics, plumbers, repairmen and test engineers.

Cyclical

Marine diesel engines are divided into four-stroke and two-stroke.The difference between the two types is essential.The four principle of action is to go through the operating cycle of the two revolutions of the crankshaft or four stroke.Active action occurs only during one cycle, the other three - the preparatory.

Single two-stroke engine cycle is performed in one revolution.The principle of the fuel mixture compression and subsequent ignition is different.In the cylinder there are so-called scavenging ports with which there is an induced purging the combustion chamber and thus there is no need exhaust through valves.The number of cycles is reduced exactly twice.

Additional differences

also a classification speed.Low-speed motors - up to 150 rev / minute and of medium - to 600 rev / min.High-speed engines for large and very large ships did not exist because of the specificity of their action, high loads and sverhprodolzhitelnoy at runtime.

Marine diesel engines for small vessels

small boats, river boats and ships equipped with the class, as a rule, a single motor.The power of such a diesel engine may be different, depending on the purpose for which the ship is intended.A pickup speedboat engines, and walking, sightseeing and cruise are set low speed motors.Coast Guard Patrol Vessels generally have two fairly heavy-duty diesel engines, one of which involved all the time, and the second turns on as needed.

Marine diesel engines for small vessels are designed for fixed installation.They are generally compact and economical, with a high resource use.Outboard motors are usually gasoline, because they have the ability to quick launch.

Diesel fuel for marine engines

For stable operation of the power plant on the vessel must use high-quality fuel (diesel fuel).Its suitability is determined by the following criteria:

  • octane;
  • resistance to detonation;
  • cetane number;
  • fractional composition;
  • combustion efficiency, the degree of opacity, toxicity;
  • viscosity and density as a factor of the normal supply to the system;
  • low temperature properties that determine the functioning;
  • levels of cleanliness;
  • flash point, in terms of the safety of use;
  • the presence of sulfur compounds, metals and unsaturated hydrocarbons as stimulants carbonization.

Classification fuel:

  • International - FO, HFO, MGO, MDO, IFO 380, IFO 380LS;
  • Russian analogue - L-62, SMT1, SMT2, F-5, DM, IFO 380;
  • Russian standard fractions - low-viscosity, medium viscosity, high viscosity, light and heavy.

basic standards adopted in Russia, regulating the quality of diesel fuel for marine engines:

  • summer "L" - used at temperatures above zero degrees Celsius;
  • winter "H" - used at temperatures up to minus 20 degrees;
  • Arctic "A" - the temperature to minus 50 degrees Celsius.
  • low-viscosity marine fuel - made TU 38.10;
  • Brand DM - the highest category to ship low-speed engines;
  • bunker fuel oil F-5 - made according to GOST 10.5.85;bunker fuel oil F-30, F-180, F-380 - are manufactured in accordance with TU 0252-003-2905.

fuel system of marine diesel engine

supply fuel in the ship's power plant by means of the fuel system in the main and auxiliary engines.Along with the main function of the system should provide:

  • loading fuel into the tanks at the base and storage;
  • clean fuel from impurities and water;
  • if necessary - the cooling nozzles;
  • separation of fuel.

receive fuel from coastal devices carried by the deck of the pipeline, which has couplings on both sides.On passenger vessels receiving fuel occurs in some isolated areas.Accepted fuel is stored in tanks under-deck and on-board tanks interconnected.All containers are equipped with pumps for which duplicate each other in case of failure of one of them.Before a vessel on a voyage on board carried out the separation and purification of fuel, then the fuel is pumped into the tank supplies.

Stamps ship engines

Energy Diesel installation is made in an amount such that trace their range is not possible.Well-known manufacturers of engines for large marine and ocean-going vessels - is:

  • Scan Diesel (Croatia).
  • Mitsubishi (Japan).
  • Hyundai (South Korea).
  • Lombardini Marine (Italy).
  • Wartsila (Finland).

A separate category includes marine diesel engines "YaMZ" produced by Yaroslavl Motor Plant.Diesel engines "YaMZ" marine medium displacement most accessible Russian shipbuilding enterprises, and at the price and quality.

ship repair power plants

Each engine operating under constant load, there is a gradual development of the natural mechanisms of the rubbing surfaces.Sooner or later there is a need for the current or overhaul.Owners are trying to carry out repairs on the spot, on their own.However, this is not always possible, as for the replacement of worn parts often requires special equipment and qualified personnel.In this case, the engine is disassembled and shipped to the manufacturer.

repair of ship diesel engine takes several months, in which case the boats are idle.However, the owner may have a backup engine, which is installed instead of removed.So it can avoid downtime, which is very costly.

Ship giants

Among marine engines have their champions.The largest marine diesel engine - model Wartsila-Sulzer-RTA96-C.Produced in the Finnish company.The model is developed taking into account the multi-variant in the line includes several kinds.Request superdvigatel can format 6 or 14 cylinders.The choice makes the customer six months before the start of work.

Bore This giant is 960 mm.Engine power - 109 thousand liters.from.Ocean container with engine easily develops a speed of 46 kilometers per hour.