Fuel/Lube Oil Systems

Objectives Why lubrication Standard shipboard lube oil system Standard shipboard fuel oil system Standard safety considerations for shipboard fuel oil and lube oil systems

Fuel Oil System Purpose Provide fuel to furnace / combustor

Service System Pumps maintain a constant press in system Accumulators Fuel flow control valve adjusted to control fuel to furnace (Auto Combustion Control) excess fuel flows back to service tanks Electrically driven main Service pumps used in port or for light off Accumulators Nitrogen bladder type 10 gals/each Used in Emergencies Fill and transfer- duh Tank stripping system- connections to low points of all fuel system tanks. Used to discharge contaminated oil, sludge and water overboard or to the settling tanks. Service system- Delivers the oil at the proper temperature, pressure and purity for proper atomization and combustion in the burner.

Tanks Storage Tanks Service Tanks Contaminated Oil Settling Tanks Integral part of the ship’s bottom Contain bulk of fuel oil Service Tanks 24 hour fuel supply For immediate use Contaminated Oil Settling Tanks Hold oil contaminated with water and debris Oil settles to top, water pumped from bottom Good oil sent to service tanks Storage tanks- hold supply for long term storage Service tanks- 24 hour supply Contaminated oil settling tanks- used to hold oil that is contaminated with water or other impurities; after the contents have settled, the water and sludge are pumped out through low suction connections and the good oil is then transferred to a storage or service tank. The tanks can be used to store oily waste until it can be disposed of without violating environmental protection laws.

Piping System Fill and Transfer System Stripping System Service System Loading oil to storage tanks Transfer oil to service tanks / other storage tank Controls Trim and List Discharge oil to other ship Stripping System used to discharge contaminated oil, sludge, and water overboard or to the settling tank Service System must deliver oil at the proper temp, press, purity Fill and transfer- duh Tank stripping system- connections to low points of all fuel system tanks. Used to discharge contaminated oil, sludge and water overboard or to the settling tanks. Service system- Delivers the oil at the proper temperature, pressure and purity for proper atomization and combustion in the burner.

Basic Main Lube Oil System Storage tanks (Sump) Cooler/Heater Pumps Attached lube oil pump (ALOP) driven by reduction gears Standby lube oil pump (SLOP) Emergency lube oil pump (ELOP) Bearings, Reduction Gears

Generic L/O System

Common Components Strainers Purifiers Prevent passage of grit, scale, dirt, and other foreign material Purifiers Separate water and sediment from oil

Lube Oil Properties Adhesivness Cohesivness Viscosity (Thickness) Ability to adhere to object surface and support weight Cohesivness Ability to hold together under load to maintain fluid film Viscosity (Thickness) Ability to maintain constant resistance to flow over varying temps

LO Properties Oxidation- The rate at which the oil deteriorates or breaks down Demulsibility- The ability to separate out water.

Lubrication Oil System Prevent metal-to-metal contact by creating film of fluid between surfaces Sliding/rolling friction replaced by fluid friction Provides pressurized oil to create fluid film Reduces heat build-up caused by friction Removes heat generated by friction since lube oil cooled

Friction Sliding - friction caused by moving surface over stationary surface Rolling - friction caused by curved body rolling on flat surface Fluid - friction caused by fluids resistance to movement

Prevent Metal to Metal Contact

Lube Oil As A Coolant Friction cannot be entirely eliminated Power still lost through the generation of heat in the bearings Energy of a few hundred horsepower may be lost in the bearings of large turbines at high power Since oil continuously pumped through system, heat is removed at cooler The foregoing discussion has been concerned with the use of lubricants to reduce friction and accompanying power losses. Friction cannot be entirely eliminated. It has been shown that fluid friction replaces dry friction, but power is still lost through the generation of heat in the bearings. Lightly loaded or slow moving bearings can dissipate the generated heat by radiation and conduction, but energy on the order of a few hundred horsepower may be lost in the bearings of large turbines at high power. Thus, an additional important function of lubricating oil is to serve as a coolant. This accomplished by circulating and cooling in a heat exchanger. The circulation has a twofold effect. It disposes of the heat generated in the bearings while simultaneously preventing the oil from reaching a temperature range where a change in its physical or chemical properties would endanger its lubricating properties.

Safety Precautions Flammable liquid at high pressure Class "B" fire

Summary