Chapter 3 (DIESEL PLANT) Flashcards
An engine in which the fuel is burned directly within the working cylinder
Internal combustion engine
An engine in which the fuel is burned outside of a cylinder
External combustion engine
An engine wherr the ignition is caused by heat of compression
Compression ignition engine
What temperature is required to ignite the fuel oil?
800 to 1000 F
What air pressure is required to produce the required ignition temperature?
350 to 500 psi
In a four stroke diesel engine, drawing air into the cylinder is what stroke?
First stroke
Compressing air into four stroke cycle is
Second stroke
Which of the following strokes is produced by the burning gases
Third stroke
Which of the following strokes expel the burned gases
Fourth stroke
Clearing a cylinder of exhaust gases by forcing into it a current air which provides clean air for the next compression stroke
Scavenging
Increasing the total amount of charging air in the working cylindr of the engine
Supercharging
The portion of the piston which extends below the piston pin and serves as a guide for the piston and connecting rod
Piston skirt
Rings located in the grooves of piston usually near the top and the near bottom
Piston ring
Binding of the piston and the cylinder wall as a result of the lubrication having been destroyed by excessive temperature and friction
Piston seizure
Grooves in the cylinder wall or piston or in both. It is caused by the piston scraping the cylinder wall in the movement without proper lubrication
Piston scoring
A device whuch automatically governs or controls the speed of an engine
Governor
A combibation of liquids which di not mix — or conbine chemically
Emulsion
What temperature should be the maximum to which lubricating oil is permitted to rise
not more than 100 F
What air pressure is needed for air starting a diesel engine?
250 psi
About what temperature will self igniting cartridges ignite?
about 190 F
The fuel is supplied by one pump and switched to each cylinder by a multi outlet rotating valve or distributor
Distributor system
This is virtually a distributor two stage pumping system that is, modified distributor system
Injector system
A chamber so proportioned with respect to the clearance volume proper of the cylinder that only about 30% of the combustion takes place within the chamber itself
Pre combustion chamber
The entire charge is ignited in the separate combustion chamber before the initial expansion takes place, forcing the burning gases through the connecting passages and against the moving piston
Separate combustion chamber
A chamber so designed that injection takes place directly opposite its outlet, the chamber extending backward from the outlet
Ante combustion chamber
Fuel is injected only into the main cylinder, during expansion of the burning gases in the main chamber, when the pressure therein drops below that of the air in the cell
Air cell chamber
What is the temperature of air in the cylinder when the Diesel engine is operating at full load
between 800 and 1100 F
What are the exhaust gas temperatures at normal operating conditions?
between 400 and 700 F
How are high speed Diesel engines started?
By an electric motor
What speeds are considered high speed diesel engine?
100 to 2000 rpm or 3000 rpm
It is a device used for atomizing or cracking fuel oil and through whuch the fuel oil is injected into the working cylinders or Diesel engines
Atomizer
What is the proper seat width of a spray valve?
1/16 in.
A cylindrical vessel connected in the fuel system to absorb the shock of the injection pumps and to provide reservoir at high pressure for supplying an even flow of fuel oil to the cylinders
Accumulator
How hot are the exhaust gases?
400 to 700 F
Which of the following is an automatic device used for keeping constant air pressure?
Unloader
What is the other term of the diameter of the circular cylinder?
Bore
What do you call the maximum distance traveled by the piston?
Stroke
Which of the followinv is the product of the cylinder area and stroke?
Swept volume
The ratio of the clearance volume to the swept volume
Fractional clearance
The piston is at maximum reach fron the crankshaft to which of the following?
Top dead center
The piston is closest to the crankshaft to whuch of the following?
Bottom dead center
Which of the following engines where the expanding combustion gases act on one end of the piston?
Single acting engine
Which of the following types of engine where the expanding conbustion gases act on both ends of the piston?
Double acting engine
The compression ratio of a Diesel engine varies from about:
13.5 to 17.5
In standard Diesel, thermal efficiency was not much higher than about what percent?
35%
A closed heat exchanger that transfers heat from compressed air to cooler air
Aftercooler
Which of the following is used to improve cold weather starting?
Glow plug
The rated power that the manufacturer claims the engine is able to provide on a continuous basis without incurring damage
Continuous duty rating
What is the peak power rating that can be produced on an occasional basis?
Intermittent rating
Which of the following is the valve of a property that includes the effect of friction?
Brake value
