Book 2: 4-21 - "Cooling Towers" Flashcards
The chimney natural draft cooling tower is also known as a _____ tower.
Select one:
A. Hypergolic
B. Condenser
C. Hyperbolic
D. Cooling water
E. Hyperbaric
C. Hyperbolic
The water to be cooled is distributed in the tower by spray nozzles and splash bars to expose a very _____ surface area to atmospheric air thus aiding evaporation.
Select one:
A. Large air
B. Large water
C. Small air
D. Small water
E. Wet water
B. Large water
Cooling towers are unquestionably the most common type of heat exchanger used when cooling water is scarce, expensive, and a temperature within _____ of the ambient wet bulb temperature is required.
Select one:
A. 15°C to 17°C (59°F to 63°F)
B. 27°C to 29°C (81°F to 85°F)
C. 4°C to 6°C (8°F to 12°F)
D. 20°C to 22°C (68°F to 72°F)
E. 10°C to 12°C (50°F to 54°F)
C. 4°C to 6°C (8°F to 12°F)
The induced draft cooling tower has one or more fans located at the top of the tower that _____ the downward flow of water.
Select one:
A. Draw air upwards against
B. Draw air upwards with
C. Draw water upwards against
D. Draw water upwards with
E. Draw air downwards against
A. Draw air upwards against
The rate of heat transfer in any cooling tower system depends on all the following except the:
Select one:
A. Area of water surface in contact with the air
B. Relative velocity of both air and water during contact
C. Difference between the inlet water temperature and the inlet air wet bulb temperature
D. Length of contact time between the air and water
E. Atmospheric pressure
E. Atmospheric pressure
A cooling tower is a device that uses a combination of heat and mass transfer to lower the temperature of the:
Select one:
A. Refrigerant
B. Chilled water
C. Cooling water
D. Condenser
E. Condensate
C. Cooling water
During cold weather operation what water basin temperature is required prior to allowing full water flow over the cooling tower fill?
Select one:
A. 20°C (68°F)
B. 32°C (90°F)
C. 27°C (81°F)
D. 10°C (50°F)
E. 15°C (59°F)
C. 27°C (81°F)
The fans at the top of the induced draft cooling tower discharge the _____ upward and away from the air entering at the bottom of the tower.
Select one:
A. Hot, moisture-laden air
B. Cool, moisture-laden air
C. Hot, dry air
D. Cool, moisture-laden water
E. Hot, moisture-laden water
A. Hot, moisture-laden air
One of the advantages of the crossflow mechanical draft tower over the counterflow tower is the _____ leading to lower energy costs.
Select one:
A. No fan requirement
B. Higher fan power requirement
C. Lower temperature requirement
D. Lower fan power requirement
E. Higher temperature requirement
D. Lower fan power requirement
Atmospheric natural draft towers are used in areas that have _____.
Select one:
A. Low winds and little water
B. Relatively constant winds and large open spaces
C. No need for a large cooling water supply and return temperature differential
D. Economical supply of electricity
E. An economical supply of cooling water
B. Relatively constant winds and large open spaces
The sides of atmospheric natural draft towers are _____ and airflows across the tower by natural currents.
Select one:
A. Sealed
B. Louvred
C. Lowered
D. Slanted
E. Solid
B. Louvred
The counterflow mechanical draft tower occupies less floor space than a crossflow tower but is _____ for a given capacity.
Select one:
A. Taller
B. Smaller
C. Faster
D. Shorter
E. Larger
A. Taller
During the operation of a forced draft cooling tower, which of these is NOT true?
Select one:
A. A fan forces air at a low velocity through the packing
B. Water entrained in the air is removed by the drift eliminators
C. Vibration and noise are at a maximum
D. The fans handle mostly dry air
E. Water flows downward
C. Vibration and noise are at a maximum
The basic components of a cooling tower include all of the following except:
Select one:
A. Cooling water circulating pumps
B. Inlet air louvres
C. Drift eliminators
D. Air moving equipment
E. Cooled water basin
A. Cooling water circulating pumps
Possible operational problems with natural draft cooling towers may include all of the following except:
Select one:
A. Excessive water drift
B. Reduction in water flow
C. High discharge water temperature from the tower
D. Low discharge water temperature from the tower
E. Tower basin or sump overflowing
D. Low discharge water temperature from the tower