Book 2 Chapter 32: Microturbines Flashcards
The turbine exhaust gas still contains a high amount of _________ which enters the boiler, where water can be heated for a hydronic system, or turned into steam for a steam system.
Heat
Which of the following are synchronized by a converter from the alternator output to meet the demand of the facility?
A) Voltage
B) Phasing
C) Frequency
D) All of the above
D) All of the above
Which of the following is the most common source of fuel supply to the micro turbine?
A) Propane
B) Kerosene
C) Light oils
D) Natural gas
D) Natural gas
Starting a microturbine:
A) Needs extensive operator input
B) Requires constant supervision
C) Is fully automatic
D) Cannot be automatic
E) Requires a large checklist
C) Is fully automatic
A microturbine system is most likely not to have a/an:
A) Rotating speed less than 50,000 rev/min
B) Heat recovery boiler on the exhaust
C) Insulation package to control noise
D) Alternator
E) Control system
A) Rotating speed less than 50,000 rev/min
What types of energy is supplied to a system by a microturbine?
A) Electricity and heat
B) Hydraulic and vibrational
C) Pulse and potential
D) Mechanical and translational
E) Kinetic and momentum
A) Electricity and heat
The lubricating fluid in a microturbine is:
A) Air
B) Mineral oil
C) Helium
D) Alcohol
E) Graphite
A) Air
A major advantage of microturbine is that they:
A) Automatically produce 60 Hz electricity
B) Are very quiet in operation
C) Produce very cool exhaust
D) Require no pressurized oil system for lubrication
E) Use steam for fuel
D) Require no pressurized oil system for lubrication
The output from a microturbine is:
A) Supplied at a constant frequency
B) In phase with the system grid
C) Connected directly to the system grid
D) Synchronized by means of a converter
E) Low frequency
D) Synchronized by means of a converter
A microturbine combined heating system consists of:
A) Reciprocating compressor, combustor, turbine, boiler and hydronic heating system
B) Axial compressor, combustor, turbine, boiler, and hydronic system
C) Rotary Gear compressor, turbine, generator
D) Recycle gas generator, turbine, boiler, incinerator
E) Compressor, gear box, flame tube, condenser
B) Axial compressor, combustor, turbine, boiler, and hydronic system
Which of the following from a microturbine-driven alternator is/are synchronized by a converter to meet the electrical demand of the facility?
1. Voltage
2. Amperage
3. Frequency
4. Resistance
5. Phase
A) 2 an 4 only
B) 3
C) 1,3,5
D) 1,2
E) 1,2,3
C) 1,3,5
The most common fuel used for microturbine is:
A) Light oil
B) Gasoline
C) Diesel fuel
D) Kerosene
E) Natural gas
E) Natural gas
For microturbine combine heating system, which of the following statements is NOT true?
A) Atmospheric air is drawn into an axial flow compressor where it is compressed
B) The rotating energy is transferred to the condenser and the alternator via a common shaft
C) Fuel is added and ignited in a very rapid combustion process
D) The compressor discharges to the combustor
E) The hot gases are allowed to expand through the gas turbine, creating rotational energy
B) The rotating energy is transferred to the condenser and the alternator via a common shaft
Boiler checks are unnecessary in the automatic microturbine combined heating system.
A) True
B) False
B) False
An undesirable feature of microturbine is:
A) Size
B) Large floor space
C) Heavy oils and fuel
D) Oil system
E) Noise
E) Noise
The main advantage of foil bearings in microturbine is:
A) The elimination of oil systems
B) The high speed of shaft rotation
C) The noise reduction
D) The anti-wear coating
E) The use of an external pressurization system
A) The elimination of oil systems
The foil bearings used in a microturbine are a type of ________ bearing.
A) Sleeve
B) Antifriction
C) Air
D) Water
E) Journal
C) Air
The exhaust gas from the microturbine in a combined heating system is:
A) Used to directly heat a building
B) Sent through a boiler or water heater
C) Exhausted directly to atmosphere
D) Recycled through the compressor
E) At about room temperature
B) Sent through a boiler or water heater
Microturbine operate at high speeds, which are typically in the range of ____________ rpm.
A) 50,000 to 100,000
B) 25,000 to 80,000
C) 25,000 to 50,000
D) 60,000 to 120,000
E) 50,000 to 120,000
E) 50,000 to 120,000
Lubrication problems are reduced in microturbines by using:
A) Preheating the oil
B) Keeping oil temperature low
C) Using foil bearings
D) Using roller bearings
E) Only synthetic oil
C) Using foil bearings
