Machinery Spaces.com

Home || Diesel engines ||Boilers||Feed systems ||Steam turbines ||Fuel treatment ||Pumps ||Valves ||Refrigeration ||

Sulzer RTA72U diesel engine -Operational guideline

The diesel engine is a type of internal combustion engine which ignites the fuel by injecting it into hot, high-pressure air in a combustion chamber. In common with all internal combustion engines the diesel engine operates with a fixed sequence of events, which may be achieved either in four strokes or two, a stroke being the travel of the piston between its extreme points. Each stroke is accomplished in half a revolution of the crankshaft.



The RTA72U is a single-acting, low-speed, two-stroke reversible marine diesel engine manufactured by New Sulzer Diesel Ltd. It is one of the RTA series engines which were introduced in 1981 and in addition to a longer stroke than the earlier RL series, it has a cylinder-head exhaust valve providing uniflow scavenging.

The bedplate is single-walled and arranged with an integral thrust bearing housing at the aft end . Cross members are steel fabrications although the centre section, incorporating the main bearing saddle tie-bolt housings, may be a steel forging. To resist crankshaft loading and transverse bending, the main bearing keeps are held down by jackbolts.

Sulzer engine
Fig: Sulzer RTA72U diesel engine

The crankcase chamber is arranged by using individual A-frames for columns which are also the mountings for the double-slippered crosshead guides. The A-frames are joined together by heavy steel plates and short angle girders to form a sturdy box frame. The A-frames in way of the thrust block are manufactured as a one-piece double column to ensure accurate mesh of the camshaft drive gears which are enclosed in this section.

Individual cast-iron cylinder blocks are bolted together to form a rigid unit which is mounted onto the A-frames. Tie bolts extend from the top of the cylinder block to the underside of the main bearing saddles. The crankshaft is semi-built, with the combined crankpin and crankweb elements forged from a single element. The journal pins are then shrunk into the crankwebs.

For all but the larger numbers of engine cylinders, the crankshaft is a single unit. The main journal and bottom-end bearings are thin-walled shells lined with white metal. The forged connecting rod has a 'table top' upper end for the mounting of the crosshead bearing. A large crosshead, with floating slippers at each end, is used. The piston rod is bolted directly to the top of the crosshead pin. The pistons are oil-cooled and somewhat shorter in length than earlier designs. There is no piston skirt. Five piston rings are fitted which are designed to rotate within their grooves.

Cylinder liners have a simple, rotationally symmetrical design with the scavenge ports at the lower end. The deep collar at the upper end is bore-cooled, as are all components surrounding the combustion chamber. Cooling water is fed from below through a water guide arranged around the liner.

Cylinder lubrication is provided by eight quills arranged around the lower edge of the collar on the liner. The more recently introduced RTA series engines all have oil-cooled pistons with oil supplied from the crosshead bearing up through the piston rod.

A piston rod gland separates the crankcase chamber from the under piston space. Various scraper and sealing rings are Fitted within the gland.

The cylinder head is a single steel forging arranged for bore cooling with appropriately drilled holes. Pockets are cut for the air starting valve and fuel injection valves, the number depending upon the cylinder bore. The centrally mounted exhaust valve is fitted in a cage with a bore-cooled valve seat.

The valve stem is fitted with a vane-type impeller to ensure valve rotation. The valve is opened by hydraulic pressure from pumps driven by the camshaft and closed by compressed air. The camshaft is located at engine mid-height and is gear driven from the crankshaft.

The initial gear drive is bolted to the rim of the thrust block and a single intermediate wheel is used. On larger-bore, high-powered engines the gear drive is in the centre of the engine. The camshaft extends the length of the engine and each individual segment carries the exhaust valve actuating and fuel-injection pumps plus the reversing servo motor for one pair of cylinders.

Constant-pressure turbocharging is used, and electrically driven blowers cut in automatically when the engine load is at about 40% of the maximum continuous rating.

Lubricating oil is supplied to a low- and a medium-pressure system. The low-pressure system supplies the main and other bearings. The crosshead bearing, reversing servo motors and exhaust valve actuators are supplied by the medium-pressure system. Cylinder oil is supplied to lubricators from a high-level service tank.

Double valve controlled, variable injection timing is used to deliver fuel to multiple, uncooled injectors and an electronic governor is supplied as standard.

Where the engine has oil-cooled pistols they will be supplied from the lubricating oil system, possibly at a higher pressure produced by booster pumps, e.g. the Sulzer RTA engine. An appropriate type of lubricating oil must be used for oil-lubricated pistons in order to avoid carbon deposits on the hotter parts of the system.








Marine diesel engine related other useful articles:
  1. Four stroke cycle diesel engines operational guideline

  2. The four-stroke cycle is completed in four strokes of the piston, or two revolutions of the crankshaft. In order to operate this cycle the engine requires a mechanism to open and close the inlet and exhaust valves
    More .....

  3. Two stroke cycle diesel engines operational guideline

  4. The two-stroke cycle is completed in two strokes of the piston or one revolution of the crankshaft. In order to operate this cycle where each event is accomplished in a very short time, the engine requires a number of special arrangements.
    More .....

  5. Power measurement for marine diesel engine - The engine indicator

  6. There are two possible measurements of engine power: the indicated power and the shaft power. The indicated power is the power developed within the engine cylinder and can be measured by an engine indicator. The shaft power is the power available at the output shaft of the engine and can be measured using a torsionmeter or with a brake.
    More .....

  7. Supply of fresh air and removal of exhaust gases by a gas exchanger

  8. A basic part of the cycle of an internal combustion engine is the supply of fresh air and removal of exhaust gases. This is the gas exchange process. Scavenging is the removal of exhaust gases by blowing in fresh air.
    More .....

  9. The fuel oil system for a diesel engine

  10. The fuel oil system for a diesel engine can be considered in two parts—the fuel supply and the fuel injection systems. Fuel supply deals with the provision of fuel oil suitable for use by the injection system.
    More .....

  11. Lubricating oil system for a marine diesel engine - how it works

  12. The lubrication system of an engine provides a supply of lubricating oil to the various moving parts in the engine. Its main function is to enable the formation of a film of oil between the moving parts, which reduces friction and wear. The lubricating oil is also used as a cleaner and in some engines as a coolant.
    More .....

  13. Cooling of ships engine - how it works , requirement of fresh water & sea water cooling system

  14. Cooling of engines is achieved by circulating a cooling liquid around internal passages within the engine. The cooling liquid is thus heated up and is in turn cooled by a sea water circulated cooler. Without adequate cooling certain parts of the engine which are exposed to very high temperatures, as a result of burning fuel, would soon fail.
    More .....

  15. Starting air system for diesel engine - how it works

  16. Diesel engines are started by supplying compressed air into the cylinders in the appropriate sequence for the required direction. A supply of compressed air is stored in air reservoirs or 'bottles' ready for immediate use. Up to 12 starts are possible with the stored quantity of compressed air.
    More .....

  17. Governor-Function of governors controlling speed of marine diesel engine

  18. The principal control device on any engine is the governor. It governs or controls the engine speed at some fixed value while power output changes to meet demand. This is achieved by the governor automatically adjusting the engine fuel pump settings to meet the desired load at the set speed.
    More .....

  19. Cylinder relief valve of a marine diesel engine - operational guideline

  20. The cylinder relief valve is designed to relieve pressures in excess of 10% to 20% above normal. The operation of this device indicates a fault in the engine which should be discovered and corrected.
    More .....

  21. Explosion relief valve of a marine diesel engine

  22. As a practical safeguard against explosions which occur in a crankcase, explosion relief valves or doors are fitted. These valves serve to relieve excessive crankcase pressures and stop flames being emitted from the crankcase. They must also be self closing to stop the return of atmospheric air to the crankcase.
    More .....

  23. Turning gear operational guideline
    The turning gear or turning engine is a reversible electric motor which drives a worm gear which can be connected with the toothed flywheel to turn a large diesel. A slow-speed drive is thus provided to enable positioning of the engine parts for overhaul purposes.
    More .....

  24. Couplings, clutches and gearboxes of a marine diesel engine

  25. The principal control device on any engine is the governor. It governs or controls the engine speed at some fixed value while power output changes to meet demand. This is achieved by the governor automatically adjusting the engine fuel pump settings to meet the desired load at the set speed.
    More .....

  26. MAN B&W diesel engine - Basic principles and operational guideline

  27. It is one of the MC series introduced in 1982, and has a longer stroke and increased maximum pressure when compared with the earlier L-GF and L-GB designs.
    More .....

  28. Crankcase oil mist detector of a marine diesel engine

  29. It is one of the MC series introduced in 1982, and has a longer stroke and increased maximum pressure when compared with the earlier L-GF and L-GB designs.
    More .....

  30. Various Heat exchanger for running machinery on board cargo ships

  31. Shell and tube heat exchangers for engine cooling water and lubricating oil cooling have traditionally been circulated with sea water. The sea water is in contact with the inside of the tubes, tube plates and water boxes.
    More .....

  32. Guideline for Turbochargers safety and operational requirement

  33. Shell and tube heat exchangers for engine cooling water and lubricating oil cooling have traditionally been circulated with sea water. The sea water is in contact with the inside of the tubes, tube plates and water boxes.
    More .....

  34. Function of Piston & piston rings

  35. Piston forms the lower part of the combustion chamber. It seals the cylinder and transmits the gas pressure to the connecting rod. The Piston comprises of two pieces; the crown and the skirt.The crown of a piston is subject to mechanical and thermal stresses.
    More .....





Marine machineries - Useful tags

Marine diesel engines ||Steam generating plant ||Air conditioning system ||Compressed air ||Marine batteries ||Cargo refrigeration ||Centrifugal pump ||Various coolers ||Emergency power supply ||Exhaust gas heat exchangers ||Feed system ||Feed extraction pump || Flow measurement || Four stroke engines || Fuel injector || Fuel oil system || Fuel oil treatment ||Gearboxes || Governor || Marine incinerator || Lub oil filters || MAN B&W engine || Marine condensers || Oily water separator || Overspeed protection devices || Piston & piston rings || Crankshaft deflection || Marine pumps || Various refrigerants || Sewage treatment plant || Propellers || Power Plants || Starting air system || Steam turbines || Steering gear || Sulzer engine || Turbine gearing || Turbochargers || Two stroke engines || UMS operations || Drydocking & major repairs || Critical machinery || Deck machineries & cargo gears || Control and instrumentation ||Fire protection ||Engine room safety ||






Machinery Spaces.com is about working principles, construction and operation of all the machinery items in a ship intended primarily for engineers working on board and those who working ashore . For any remarks please Contact us

Copyright © 2010-2016 Machinery Spaces.com All rights reserved.
Terms and conditions of use
Read our privacy policy|| Home page||