Tpc 435 Condensers And Cooling Towers

Question 1

The capacity of a condenser is affected by the

area of contact with the cooling medium heat absorbed in the evaporator
superheat in the suction line
type of refrigerant used

Answer 1

area of contact with the cooling medium

Question 2

Natural-draft air-cooled condensers and forced-air condensers are alike in that both types

are of the same size for a given capacity
can be used on systems of any size
depend on air circulating over the coils
use either centrifugal or propeller fans

Answer 2

depend on air circulating over the coils

Question 3

Low-ambient control in air-cooled condenser can be achieved by

activating the pressure-relief valve adding a receiver
changing the type of refrigerant
closing the dampers

Answer 3

closing the dampers

Question 4

Spring-loaded relief valves protect a system against explosion by acting in response to high_____. Fusible plugs act in response to high ____

• pressure; temperature
• temperature; pressure
• temperature; voltage
• voltage; temperature

Answer 4

pressure; temperature

Question 5

Periodic maintenance of air-cooled condensers includes doing which of the following every three months?

Checking all belts and pulleys
Checking the operation against a P-H chart
Measuring the ambient temperature
Removing and replacing the refrigerant

Answer 5

Checking all belts and pulleys

Question 6

In the_____ system, water passes through the condenser to cool the refrigerant. The water is then ____

counterflow, pumped in reverse
evaporative; vaporized
makeup; chemically treated
wastewater ; discharged to the sewer

Answer 6

wastewater ; discharged to the sewer

Question 7

In a water-cooled condenser system, “makeup water” is used for

increasing the concentration of minerals
mixing with acid or other chemicals
reducing the amount of scale on the tubes
replacing water lost through evaporation

Answer 7

replacing water lost through evaporation

Question 8

Tube in-tube, shell-and-coil, and shell-and-tube condensers are alike in the following way(s):

liquid refrigerant collects at the bottom
refrigerant vapor rises from the bottom water enters from the top
water surrounds the refrigerant tube

Answer 8

liquid refrigerant collects at the bottom

Question 9

A condenser has a pressure relief device that ____ if the refrigerant pressure becomes too high.

closes the inlet line
increases the flow of water
releases refrigerant
starts the compressor motor

Answer 9

releases refrigerant

Question 10

Generally, how long should you allow a chemical cleaner to stand in a condenser?

A few days
A few hours
A few minutes
Not at all

Answer 10

A few hours

Question 11

What type of cooling tower is shown in the drawing below?

Forced draft, counterflow
Forced draft, crossflow
Induced draft, counterflow
Natural draft, parallel flow

Answer 11

Induced draft, counterflow

Question 12

Which components in the water-circulating system for a cooling tower or spray pond are used to keep the concentration of minerals low?

Bleedoff valve
Deionizer
Drift eliminator
Pressure-relief bypass valve

Answer 12

Bleedoff valve

Question 13

The capacity of a cooling tower can be controlled by means of (a)

changes in the cooling load
diverting valve
remote indoor water tank
variations in wet-bulb temperature

Answer 13

diverting valve

Question 14

As part of maintaining a cooling tower, you should check the _____ everyday.

belts and pulleys for wear
fan blades for bends and nicks
float valve for clogging
oil in the fan speed reducer for dirt

Answer 14

float valve for clogging

Question 15

The basic classifications for evaporative condensers are

air-cooled and water-cooled
blow-through and draw-through
forced draft and natural draft series flow and parallel flow

Answer 15

blow-through and draw-through

Question 16

An evaporative condenser may include a desuperheating coil for the purpose of

eliminating the need for fins on the coil preventing flash gas in the liquid line reducing the condenser’s capacity
reducing the formation of scale

Answer 16

reducing the formation of scale

Question 17

Which of the following methods will maintain condensing pressure during cold weather operation?

circulating water intermittently
changing the refrigerant daily
increasing air supply
moving the unit indoors

Answer 17

circulating water intermittently

Question 18

What will prevent the water in an evaporative condenser from freezing during cold weather?

Increasing the airflow
Installing a sump heater
Reducing dissolved minerals
Running the system only on mild days

Answer 18

Installing a sump heater

Question 19

As a part of maintaining an evaporative condenser you should check the ______ every three months.

bleedoff line for proper flow
fan blades for tightness
spray nozzles for clogging
system for unusual noises

Answer 19

fan blades for tightness

Question 20

One of the main categories of water-related problems in an air-conditioning or refrigeration system is

algae
corrosion
minerals
pH

Answer 20

corrosion

Question 21

Corrosion in a water-cooled system can be caused by

biological organisms
scale
silt
wax

Answer 21

biological organisms

Question 22

Scale formation can be reduced in a refrigeration system by adding _____ to the cooling water.

acid
calcium sulfate
chlorine
copper sulfate

Answer 22

acid

Question 23

Bacteria and algae can be controlled in a refrigeration system by adding _____ to the cooling water.

acid
chlorine
lignin
polyphosphates

Answer 23

chlorine

Question 24

Chemical deterioration in a wooden cooling tower can be controlled by

adding chlorine to the water
keeping the pH of circulating water in the 6.0 to 7.5 range
spraying the wood with materials that are toxic to fungi
using non-oxidizing biocides

Answer 24

keeping the pH of circulating water in the 6.0 to 7.5 range

Question 25

Which of the following can increase the capacity of a cooling tower or a spray pond by the greatest amount? • Decrease in air velocity across the surface • Decrease in dry-bulb temperature of the air • Increase in air velocity across the surface • Increase in dry-bulb temperature of the air

Answer 25

• Decrease in air velocity across the surface