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Russian Marine Propulsion

Ship's propulsion providing the movement of ships, boats and other vessels. Propellers include a propeller and a paddle wheel. As a ships power plants, steam engines and turbines, gas turbines and internal combustion engines, mainly diesel, are used. Large and powerful specialized vessels such as icebreakers and submarines often use nuclear power plants.

Apparently Leonardo da Vinci (14521519) was the first to propose the use of steam energy for the movement of ships. In 1705, T. Newcomen (England) patented the first fairly efficient steam engine, but his attempts to use the reciprocating piston to rotate the propeller were unsuccessful. Steam is a traditional source of energy for ship traffic. Steam is produced by burning fuel in water tube boilers. Most often, double-drum water tube boilers are used. In these boilers there are fire chambers with water-cooled walls, superheaters, economizers, and sometimes air heaters. Their efficiency reaches 88%.

Diesel engines first appeared as marine engines in 1903. Fuel consumption of marine diesels is 0.25-0.3 kg / kW h, and steam engines consume 0.3-0.5 kg / kW h depending on the engine design , drive and other design features. Diesels, especially in combination with an electric drive, are very convenient for use on ferries and tugboats, as they provide high maneuverability.

The times of reciprocating machines that once served a wide variety of purposes have passed. In terms of efficiency, they are significantly inferior to both steam turbines and diesel engines. On those ships where steam engines are still standing, this is a compound machine: steam expands sequentially in three or even four cylinders. The pistons of all cylinders operate on a single shaft.

Ship steam turbines usually consist of two stages: high and low pressure, each of which rotates the propeller shaft through a reduction gear. On naval vessels often additionally put small turbines for the cruising regime, which are used to increase efficiency, and powerful turbines are turned on at maximum speeds. The high-pressure stage rotates at a speed of 5000 rpm. On modern steam vessels, feed water from condensers to heaters is supplied through several heating stages. Heating is due to the heat of the working fluid of the turbine and exhaust flue gases flowing around the economizer.

Marine engineEfficiencyterms of UseType of fuelStaff safetyEnvironmental effectStart timeDimensionsMaterials of manufacture
Diesel Internal combustion engine30% -36%Increased noise, the presence of rectilinear-return movement of the working partsFuel oil, dieselLow hazard to personnelExhaust Emissions IncreasedAlmost instantlyBulky (with increased power), lack of a large number of auxiliary equipmentHigh strength materials for cylinders, moving parts
Steam engine8% -15%Ease of maintenanceAlmost any type of fuelHigh securityEmission of toxic gases into the atmosphereHalf an hour to a few hoursBulky, a large number of accessoriesHigh strength materials for cylinders, moving parts
Steam turbine30% -35%Increased service at rated dutyCoal, fuel oilRelative danger due to work with high working environmentEmission of toxic gases into the atmosphere, draining of hot intake waterHalf an hour to a few hoursBulky, a large number of accessoriesHeat-resistant, heat-resistant materials for a turbine and basic equipment
Gas turbine25% -30%Minimal maintenance, increased reliabilityGas, fuel oilHigh safety at rated operationEmission of toxic gases with a sufficiently high temperature15-30 minutesCompact, lack of a large number of accessoriesHeat-resistant materials for the blades of the first stages of the turbine
Nuclear power plant35% -40%Continuous process controlNuclear fuel (uranium-235, plutonium, etc.)High hazard due to radiationSpent radioactive wasteA few days when starting from a cold state, from a hot state - minutesBulky, a large number of accessoriesHigh strength and expensive personnel protection materials



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Page last modified: 23-01-2020 17:46:57 ZULU