What is the function of the concentrator (generator)?
a) To cool the refrigerant vapour
b) To increase the absorbency potential of used Lithium Bromide
c)...
What is the function of the concentrator (generator)?
In comparing absorption and compression refrigeration systems, which of the following comparisons is true?
In comparing absorption and compression refrigeration systems, which of the following comparisons is true?
a. Slugs of liquid carried over from the...
In order to lower the boiling point of the refrigerant in the lithium bromide refrigeration system it is important that the system maintain
In order to lower the boiling point of the refrigerant in the lithium bromide refrigeration system it is important that the system maintain
a. An...
The absorber in the lithium bromide refrigeration system is equipped with a pump
The absorber in the lithium bromide refrigeration system is equipped with a pump
a. To force water into a finely divided state
b. To decrease contact...
In a lithium bromide refrigeration system, the _____ lithium bromide solution has the ability to absorb water vapour readily.
In a lithium bromide refrigeration system, the _____ lithium bromide solution has the ability to absorb water vapour readily.
a. Hot
b. Cold
c. White
d....
In the ammonia absorption refrigeration system the generator is used to convert the _____ aqua to _____ aqua.
In the ammonia absorption refrigeration system the generator is used to convert the _____ aqua to _____ aqua.
a. Strong, weak
b. Weak, strong
c. Hot,...
In an ammonia absorption refrigeration system, the _____ ammonia is absorbed by the _____ aqua.
In an ammonia absorption refrigeration system, the _____ ammonia is absorbed by the _____ aqua.
a. Vaporized, weak
b. Vaporized, strong
c. Liquid,...
In an absorption refrigeration system, the compressor used in a compression refrigeration system is eliminated. Instead, the compressor's functions are performed by the:
In an absorption refrigeration system, the compressor used in a compression refrigeration system is eliminated. Instead, the compressor's functions...
In the lithium bromide absorption refrigeration system the generator is used to convert the _____ solution to a _____ solution.
In the lithium bromide absorption refrigeration system the generator is used to convert the _____ solution to a _____ solution.
a. Strong, weak
b....
Which of the following is not found on the low side of an ammonia absorption refrigeration system?
Which of the following is not found on the low side of an ammonia absorption refrigeration system?
a. Evaporator
b. Generator
c. Absorber
d. Chilled...
Ammonia systems are seldom used for air conditioning purposes in large building mainly because ammonia:
Ammonia systems are seldom used for air conditioning purposes in large building mainly because ammonia:
a. Systems require more power than most building...
In a Lithium Bromide refrigeration system, which of the following is the refrigerant?
In a Lithium Bromide refrigeration system, which of the following is the refrigerant?
a. Lithium Bromide
b. Ammonia
c. Freon-22
d. Water
e. Strong...
In an Ammonia Absorption refrigeration system, what is used as the absorbent?
In an Ammonia Absorption refrigeration system, what is used as the absorbent?
a. Ammonia
b. Air
c. Lithium Bromide
d. Water
e. Freon
Answer:...
Which of the following statements about Lithium bromide absorption refrigeration systems is false?
Which of the following statements about Lithium bromide absorption refrigeration systems is false?
a. Lithium bromide solution has the ability to...
Most absorption refrigeration systems are put in place where there is cheap excess or waste heat available. What is this heat primarily used for?
Most absorption refrigeration systems are put in place where there is cheap excess or waste heat available. What is this heat primarily used for?
a....
In the Lithium Bromide refrigeration system, what is the function of the concentrator (generator)?
In the Lithium Bromide refrigeration system, what is the function of the concentrator (generator)?
a. To exchange heat between the high temperature...
Which of the following steps is not a step in the startup of a reciprocating or rotary compressor refrigerating system?
Which of the following steps is not a step in the startup of a reciprocating or rotary compressor refrigerating system?
a) Check oil level in the...
When a chiller has stopped due to low water temperature, and the chilled water temperature subsequently rises approximately 5-6°C above the chilled water temperature set point, the:
When a chiller has stopped due to low water temperature, and the chilled water temperature subsequently rises approximately 5-6°C above the chilled...
To avoid liquid slugging in a direct expansion evaporator after shutting down a reciprocating or rotary compressor refrigerating system which of the following measures needs to be taken?
To avoid liquid slugging in a direct expansion evaporator after shutting down a reciprocating or rotary compressor refrigerating system which of the...
If a refrigeration compressor fails to start but the motor is running, which of the following could be a cause?
If a refrigeration compressor fails to start but the motor is running, which of the following could be a cause?
a. The control circuit is open
b....
A system of regularly scheduled inspections and lubrications along with the adjustments, minor parts replacement and minor repairs necessary to keep the refrigerating plant and equipment in good operating condition is defined as what:
A system of regularly scheduled inspections and lubrications along with the adjustments, minor parts replacement and minor repairs necessary to keep...
Which of the following steps is not part of the start-up procedure of a centrifugal compressor refrigerating system?
Which of the following steps is not part of the start-up procedure of a centrifugal compressor refrigerating system?
a. Operate the oil pump for...
A safety control designed to protect the chiller from freezing is the:
A safety control designed to protect the chiller from freezing is the:
a. Vane closed switch
b. Low oil pressure shut down switch
c. Motor demand...
An entire centrifugal compressor refrigerating system, including the auxiliary equipment, can be stopped by simply pressing a stop button, unless
An entire centrifugal compressor refrigerating system, including the auxiliary equipment, can be stopped by simply pressing a stop button, unless
a....
Electrical starters and contractors should be inspected
Electrical starters and contractors should be inspected
a. Daily
b. Weekly
c. Monthly
d. Semi-annually
e. Annually
Answer:...
The safety control of a centrifugal compressor, that ensures the compressor only starts under a no-load condition is called the
The safety control of a centrifugal compressor, that ensures the compressor only starts under a no-load condition is called the
a. Low Oil Pressure...
Over charging the system with refrigerant will create:
Over charging the system with refrigerant will create:
a. The formation of bubbles in the sight glass
b. A high discharge condition
c. A low-pressure...
Which of the following steps is not part of a start-up of a reciprocating or rotary compressor refrigerating system?
Which of the following steps is not part of a start-up of a reciprocating or rotary compressor refrigerating system?
a. Check for proper oil level...
When some refrigeration systems are to be shut down for a prolonged period of time they should be "pumped down" and the refrigerant stored in the:
When some refrigeration systems are to be shut down for a prolonged period of time they should be "pumped down" and the refrigerant stored in the:
a....
If the chilled water temperature drops approximately 2.5-3°C below the chilled water temperature set point, the chilled water low temperature cut out will:
If the chilled water temperature drops approximately 2.5-3°C below the chilled water temperature set point, the chilled water low temperature cut out...
The chilled water flow switch prevents the:
The chilled water flow switch prevents the:
a. Cooling tower fan from starting if chilled water flow has not been established
b. Cooling tower fan...
When pumping down a refrigeration system it is recommended to leave _______ residual pressure in the system to prevent air being drawn in through minor leaks or compressor shaft seals.
When pumping down a refrigeration system it is recommended to leave _______ residual pressure in the system to prevent air being drawn in through minor...
Oil added to refrigeration compressors
Oil added to refrigeration compressors
a) is done when the compressor discharge valve is closed
b) is done with a vacuum on the crankcase
c) is done...
When charging a refrigeration system it
When charging a refrigeration system it
a) should be done to the condenser
b) should be done with the cooling water shut off
c) should be done to...
Charging a refrigeration system
Charging a refrigeration system
a) is done with the expansion valve closed
b) is done by adding refrigerant between the liquid shutoff valve and...
A sulphur candle is a test for
A sulphur candle is a test for
a) freon leaks
b) ammonia leaks
c) air leaks
d) vacuum seal
e) CFC leaks
Answer:...
Which of the following is not a recommended step for the procedure in which dry nitrogen is used for a system leak test?
Which of the following is not a recommended step for the procedure in which dry nitrogen is used for a system leak test?
a) Remove controls and...
Leak testing on a refrigeration system
Leak testing on a refrigeration system
a) is done with a sulphur stick for freon refrigerant
b) is done with litmus paper for freon
c) is done with...
Positive pressure testing of a new refrigeration system may be done
Positive pressure testing of a new refrigeration system may be done
a. Using litmus paper
b. By filling the system with oxygen
c. By filling the...
The initial refrigerant charge is added to
The initial refrigerant charge is added to
a. The high-pressure side of the system
b. At the suction of the compressor
c. The evaporator
d. The expansion...
When initially charging a refrigeration system:
When initially charging a refrigeration system:
a. the liquid line shutoff valve must be open
b. the system is charged with liquid refrigerant
c....
The refrigerant liquid charging valve connection is:
The refrigerant liquid charging valve connection is:
a. On the condenser
b. On the compressor suction crossover valve
c. On the liquid line after...
When using lighted sulphur candles to test for ammonia leaks in a refrigeration system, the presence of ammonia will be indicated by:
When using lighted sulphur candles to test for ammonia leaks in a refrigeration system, the presence of ammonia will be indicated by:
a. A change...
Before operating a new refrigeration plant, or one in which piping alterations have been made, the system must be tested for:
Before operating a new refrigeration plant, or one in which piping alterations have been made, the system must be tested for:
a. High pressure
b....
Which of the following is NOT a problem associated with excessive head pressure in a refrigeration plant?
Which of the following is NOT a problem associated with excessive head pressure in a refrigeration plant?
a. increased power consumption
b. decreased...
Which of the following statements about adding oil to a system is true?
Which of the following statements about adding oil to a system is true?
a. Oil is added by charging it into the crankcase
b. Because the crankcase...
Which of the following statements about manual refrigeration system purgers is false?
Which of the following statements about manual refrigeration system purgers is false?
a. Gas being vented into the atmosphere must pass through a...
The liquid line shutoff valve of a refrigeration system is:
The liquid line shutoff valve of a refrigeration system is:
a. Used when purging the system
b. A regulating valve
c. Used to relieve pressure
d....
What can cause a high discharge pressure in a refrigeration system?
What can cause a high discharge pressure in a refrigeration system?
a. Low evaporator level
b. Too much cooling water to the condenser
c. Over purging...
It is very important to slowly open oil drain valves and plugs in the crankcase for which of the following reasons?
It is very important to slowly open oil drain valves and plugs in the crankcase for which of the following reasons?
a. The oil is very hot
b. Oil...
Moisture in a system can result in which of the following?
Moisture in a system can result in which of the following?
a) formation of ice
b) acid formation
c) corrosion
d) deterioration of motor insulation
e)...
Which of the following statements about strainers is false?
Which of the following statements about strainers is false?
a. Strainers prevent foreign particles from damaging compressor valves
b. Piping must...
Which of the following statements about refrigeration pressure gauges is true?
Which of the following statements about refrigeration pressure gauges is true?
a. They indicate pressures and corresponding temperatures in a system.
b....
A liquid trap located in the suction line before a refrigeration compressor, which evaporates liquid refrigerant and returns it to the compressor as a gas, is called:
A liquid trap located in the suction line before a refrigeration compressor, which evaporates liquid refrigerant and returns it to the compressor as...
A chemical dot placed under the lens of a sight glass that is exposed to liquid refrigerant monitors
A chemical dot placed under the lens of a sight glass that is exposed to liquid refrigerant monitors
a. Liquid flow
b. Refrigerant levels
c. The...
The emergency discharge line of a refrigeration system:
The emergency discharge line of a refrigeration system:
a. Is located only on the condenser
b. Must have a manually-operated emergency discharge...
An emergency discharge system is installed on a refrigeration system to prevent serious conditions, such as
An emergency discharge system is installed on a refrigeration system to prevent serious conditions, such as
a. Over-charging
b. Toxic refrigerant...
A refrigeration system contains 30 kg of an A1 refrigerant. Which of the following system locations does NOT require a stop valve, according to CSA B52 code?
A refrigeration system contains 30 kg of an A1 refrigerant. Which of the following system locations does NOT require a stop valve, according to CSA...
One function of vibration absorbers is to:
One function of vibration absorbers is to:
a. Lower noise levels
b. Allow the load on the system to increase dramatically without straining the components...
A pressure relief device on a refrigeration system shall have sufficient capacity to prevent the pressure in the pressure vessel from rising more than _____ above the setting of the pressure relief device.
A pressure relief device on a refrigeration system shall have sufficient capacity to prevent the pressure in the pressure vessel from rising more than...
According to CSA B52 code, refrigerant discharge from a pressure relief device to the atmosphere shall not be less _____ from any window, ventilation opening or exit in any building.
According to CSA B52 code, refrigerant discharge from a pressure relief device to the atmosphere shall not be less _____ from any window, ventilation...
Which of the following pipe joints are permitted for high pressure 31.75 mm or smaller steel piping?
Which of the following pipe joints are permitted for high pressure 31.75 mm or smaller steel piping?
a. Silver brazed
b. Screwed
c. Soldered
d. Flared
e....
A direct expansion type evaporator that has more than one refrigerant circuit requires __________ to provide even refrigerant flow in each circuit.
A direct expansion type evaporator that has more than one refrigerant circuit requires __________ to provide even refrigerant flow in each circuit.
a....
The accessory that maintains efficient heat transfer by collecting oil that coats the tubes of the condenser is called:
The accessory that maintains efficient heat transfer by collecting oil that coats the tubes of the condenser is called:
a. Strainer
b. A strainer-drier
c....
One method of controlling the capacity of reciprocating compressors is to bypass the discharge from one or more cylinders back to the suction side of the compressor. The control is called
One method of controlling the capacity of reciprocating compressors is to bypass the discharge from one or more cylinders back to the suction side of...
Which of the statements about automatic expansion valves is false?
Which of the statements about automatic expansion valves is false?
a) The valve maintains constant pressure in the evaporator during compressor operation...
A method of controlling the capacity of reciprocating refrigeration compressors, whereby the discharge of high-pressure refrigerant is re-introduced to the suction side of the compressor, is called:
A method of controlling the capacity of reciprocating refrigeration compressors, whereby the discharge of high-pressure refrigerant is re-introduced...
The most widely used refrigerant metering device, which consists of a pressure-sensitive bellows or diaphragm connected to a temperature sensing bulb, is a/an:
The most widely used refrigerant metering device, which consists of a pressure-sensitive bellows or diaphragm connected to a temperature sensing bulb,...
The simple, small-bore device that restricts the flow of liquid from the condenser to the evaporator and maintains a pressure difference between the two, is called:
The simple, small-bore device that restricts the flow of liquid from the condenser to the evaporator and maintains a pressure difference between the...
In a refrigeration system controlled by a high-pressure float valve, excessive refrigerant charge will cause
In a refrigeration system controlled by a high-pressure float valve, excessive refrigerant charge will cause
a. Liquid carry-over to the compressor
b....
The type of operation that stops a refrigeration compressor when the temperature setpoint of the cooled substance is reached, then re-starts the compressor when the temperature set-point is exceeded, is called:
The type of operation that stops a refrigeration compressor when the temperature setpoint of the cooled substance is reached, then re-starts the compressor...
Which of the following statements about the evaporator bypass dampers in a refrigeration system is true?
Which of the following statements about the evaporator bypass dampers in a refrigeration system is true?
a. They decrease the resistance to...
The automatic expansion valve in a refrigeration system operates on the principle of balancing:
The automatic expansion valve in a refrigeration system operates on the principle of balancing:
a. The volumetric expansion of a fluid against a return...
In refrigeration systems, the most common methods used to control the capacity of a reciprocating compressor are:
In refrigeration systems, the most common methods used to control the capacity of a reciprocating compressor are:
a. Cylinder bypass and hot gas bypass
b....
What will the effect be if insufficient liquid refrigerant is admitted to the evaporator by a thermostatic expansion valve?
What will the effect be if insufficient liquid refrigerant is admitted to the evaporator by a thermostatic expansion valve?
a. Insufficient force...
The device that guides refrigerant vapour into a centrifugal compressor in the same direction as the compressor impeller is turning, is called a
The device that guides refrigerant vapour into a centrifugal compressor in the same direction as the compressor impeller is turning, is called a
a....
Sectional evaporators, installed in a refrigeration plant, control their capacity by
Sectional evaporators, installed in a refrigeration plant, control their capacity by
a. Varying the quantity of air passing over the evaporator coils
b....
In a refrigeration system controlled by a high pressure float valve, insufficient refrigerant charge will cause
In a refrigeration system controlled by a high pressure float valve, insufficient refrigerant charge will cause
a. Automatic system shut down
b. A...
The thermostatic expansion valve operates on the principle of balancing:
The thermostatic expansion valve operates on the principle of balancing:
a. The volumetric expansion of a fluid against a return spring
b. Evaporator...
In a refrigeration system, a weighted valve pin is used in a high-pressure float valve system in order to:
In a refrigeration system, a weighted valve pin is used in a high-pressure float valve system in order to:
a. Get proper pressure drop into the evaporator
b....
The control used in a mechanical refrigeration system to maintain a constant level of liquid refrigerant in the accumulator tank of a flooded evaporator is called
The control used in a mechanical refrigeration system to maintain a constant level of liquid refrigerant in the accumulator tank of a flooded evaporator...
Manual or hand-operated expansion valves are seldom used in modern refrigeration systems except, occasionally:
Manual or hand-operated expansion valves are seldom used in modern refrigeration systems except, occasionally:
a. To control the temperature of the...
Which of the following is NOT a refrigerant metering device?
Which of the following is NOT a refrigerant metering device?
a. Low-pressure float
b. Automatic expansion valve
c. Thermostat
d. Capillary tube
e....
Safety controls serve what function?
Safety controls serve what function?
a) They stop operation if the temperature gets too high.
b) They stop operation when the pressure gets too high.
c)...
Which of the following actuating control valves is electromagnetically operated?
Which of the following actuating control valves is electromagnetically operated?
a) Thermostat valve
b) Fluid expansion regulator valve
c) Evaporator...
Starting, stopping or unloading of the compressor is usually done by all of the following operating controls except
Starting, stopping or unloading of the compressor is usually done by all of the following operating controls except
a) temperature actuated control
b)...
The CSA B52 code requires that pressure limiting devices shall be provided on all systems operating above atmospheric pressure, except on a factory sealed system containing less than _____ of group A1 refrigerant:
The CSA B52 code requires that pressure limiting devices shall be provided on all systems operating above atmospheric pressure, except on a factory...
The safety control that uses a current transformer with a resistor in the motor circuit is known as:
The safety control that uses a current transformer with a resistor in the motor circuit is known as:
a. High motor temperature cut-out
b. Low oil...
With regard to their application in refrigeration systems, which of the following statements about flow switches is false?
With regard to their application in refrigeration systems, which of the following statements about flow switches is false?
a. They are used on chilled...
A refrigeration compressor's oil pressure failure switch uses a _________ element as part of its operating mechanism.
A refrigeration compressor's oil pressure failure switch uses a _________ element as part of its operating mechanism.
a. Fluid expansion
b. Bimetallic
c....
The oil-pressure failure switches of a mechanical refrigeration system
The oil-pressure failure switches of a mechanical refrigeration system
a. keep the compressor oil pressure at a level where the oil will not freeze
b....
An operating control, which consists of a hygroscopic element made of material similar to multiple strands of human hair, is called a:
An operating control, which consists of a hygroscopic element made of material similar to multiple strands of human hair, is called a:
a. Humidistat
b....
With regard to the high pressure side, the maximum setting for a pressure limiting device on a refrigeration system shall not exceed the pressure relief device setpoint by:
With regard to the high pressure side, the maximum setting for a pressure limiting device on a refrigeration system shall not exceed the pressure relief...
The expansion valve in a refrigeration system
The expansion valve in a refrigeration system
a. Expands the liquid to the receiver
b. Relieves high pressure in the receiver
c. Regulates the liquid...
With regard to a refrigeration system pressurestat, which of the following statements is false?
With regard to a refrigeration system pressurestat, which of the following statements is false?
a. The control is connected to the suction line of...
In many cases, the evaporator pressure of a refrigeration system must not fall below a certain level, in order to prevent
In many cases, the evaporator pressure of a refrigeration system must not fall below a certain level, in order to prevent
a. Frosting of coils
b....
The refrigeration compressor's operating control that uses a bimetal element is a:
The refrigeration compressor's operating control that uses a bimetal element is a:
a. Fluid expansion actuating control
b. Pressurestat
c. Humidistat
d....
Evaporative condenser can save up to __ to __ percent in water consumption
Evaporative condenser can save up to __ to __ percent in water consumption
a. 50 to 60
b. 60 to 70
c. 70 to 80
d. 80 to 90
Answer:...
Which one is NOT true about the shell and tube condenser?
Which one is NOT true about the shell and tube condenser?
a. High maintenance cost
b. High cooling efficiency
c. Cleaned easily
d. Used in medium...
Which of the following are direct expansion evaporators and flooded evaporators? 1. bare tube 2. the plate surface 3. the shell and tube 4. the finned tube
Which of the following are direct expansion evaporators and flooded evaporators?1. bare tube2. the plate surface3. the shell and tube4. the finned tube
a....
Which of the following are direct expansion evaporators? 1. bare tube 2. the plate surface 3. the shell and tube 4. the finned tube
Which of the following are direct expansion evaporators?1. bare tube2. the plate surface3. the shell and tube4. the finned tube
a. 1,3
b. 2,3
c....
Bare tube evaporators are applied where the space temperature is maintained below
Bare tube evaporators are applied where the space temperature is maintained below
a. 3C
b. 2C
c. 1C
d. 0C
e. -1C
Answer:...
The common types of evaporators used in refrigeration systems are: 1. bare tube 2. the shell and coil 3. the plate surface 4. the shell and tube 5. double tube 6. the finned tube
The common types of evaporators used in refrigeration systems are:1. bare tube2. the shell and coil3. the plate surface4. the shell and tube5. double...
The purpose of a condenser in a refrigeration system is
The purpose of a condenser in a refrigeration system is
a) to remove the sensible heat from the refrigerant
b) to remove the latent heat from the...
Defective condenser operation is a result of the presence of all of the following except
Defective condenser operation is a result of the presence of all of the following except
a) scale forming chemicals
b) dirty cooling water
c) non-condensable...
The common types of water-cooled condensers used in refrigeration systems are: 1. the shell and tube 2. the shell and coil 3. the double tube 4. the plate surface
The common types of water-cooled condensers used in refrigeration systems are:1. the shell and tube2. the shell and coil3. the double tube4. the plate...
Which of the following statements about the shell and tube evaporator type is false?
Which of the following statements about the shell and tube evaporator type is false?
a) It is also known as a chiller.
b) This type of evaporator...
The amount of water used in the evaporative condenser of a refrigeration plant is only a small percentage of that used in a water condenser of the same capacity, because
The amount of water used in the evaporative condenser of a refrigeration plant is only a small percentage of that used in a water condenser of the same...
Which of the following statements about the shell and tube refrigeration evaporator is false?
Which of the following statements about the shell and tube refrigeration evaporator is false?
a. It is also known as a chiller
b. The brine circulates...
All refrigeration evaporators:
All refrigeration evaporators:
a. require regular defrosting
b. are part of the high side of the system
c. are located between the expansion valve...
Of the following refrigeration system evaporators, the ___________ evaporators require the greatest refrigerant charge.
Of the following refrigeration system evaporators, the ___________ evaporators require the greatest refrigerant charge.
a. Direct expansion
b. Bare...
The refrigeration condenser design that requires the tubes to be cleaned with acid and then neutralized, is the:
The refrigeration condenser design that requires the tubes to be cleaned with acid and then neutralized, is the:
a. Shell and tube condenser
b. Shell...
Which of the following statements about double tube refrigeration condensers is true?
Which of the following statements about double tube refrigeration condensers is true?
a. They consist of two separate tubes side by side
b. They are...
With regard to refrigeration systems, large-capacity air-cooled condensers are found mainly
With regard to refrigeration systems, large-capacity air-cooled condensers are found mainly
a. on roof tops
b. in indoor mechanical rooms, with ductwork...
Dry and flooded evaporators differ principally in what respect?
Dry and flooded evaporators differ principally in what respect?
a. The dry evaporator is designed to cool gases only
b. The heat transfer surfaces...
Which of the following is NOT a form of refrigeration evaporator construction?
Which of the following is NOT a form of refrigeration evaporator construction?
a. Bare tube
b. Plate surface
c. Shell and tube
d. Finned tube
e. Double-tube
Answer:...
The refrigeration evaporator that increases heat exchange by crimping several thin metal plates to single-wall tubes is a
The refrigeration evaporator that increases heat exchange by crimping several thin metal plates to single-wall tubes is a
a. Plate surface evaporator
b....
An evaporator that contains only a small amount of liquid refrigerant at any time is what type of evaporator?
An evaporator that contains only a small amount of liquid refrigerant at any time is what type of evaporator?
a. Dry evaporator
b. Flooded evaporator
c....
The amount of heat absorbed by water when it evaporates at atmospheric pressure is
The amount of heat absorbed by water when it evaporates at atmospheric pressure is
a. 99.63 kJ/kg
b. 335 kJ/kg
c. 417.46 kJ/kg
d. 2257 kJ/kg
e. 2675.5...
Which of the following is NOT a common type of refrigeration condenser?
Which of the following is NOT a common type of refrigeration condenser?
a. Flooded
b. Air-cooled
c. Shell and tube
d. Shell and coil
e. Double tube
Answer:...
In a refrigeration system, which of the following is NOT a cause of poor condenser performance?
In a refrigeration system, which of the following is NOT a cause of poor condenser performance?
a. Waterside scale accumulation
b. Oil film accumulation...
An evaporator that can easily be cleaned and defrosted manually without interrupting the cooling process is which type of evaporator?
An evaporator that can easily be cleaned and defrosted manually without interrupting the cooling process is which type of evaporator?
a. Bare finned...
A compressor seal is required to prevent:
A compressor seal is required to prevent:
a. Refrigerant and oil leakage into the compressor
b. Refrigerant and oil leakage along the shaft
c. Prevent...
The function of a safety heads is to:
The function of a safety heads is to:
a. Relieve the pressure of compression when the compressor cycles off
b. Relieve the pressure in the cylinder...
Which part is not a part of a reciprocating compressor?
Which part is not a part of a reciprocating compressor?
a. Inlet vane
b. Crankshaft
c. Connecting rod
d. Piston
Answer:...
Consider a single stage, single acting reciprocating compressor. Calculate the piston displacement in cubic metres per minute, if given the following: piston stroke 12 cm piston diameter 10 cm piston speed 1100 working strokes per minute
Consider a single stage, single acting reciprocating compressor.Calculate the piston displacement in cubic metres per minute, if given the following:piston...
Which one is NOT true about rotating mechanical seals
Which one is NOT true about rotating mechanical seals
a. Low cost
b. Less maintenance
c. Reduced wear on rotating shafts
d. Leakage is reduced to...
Packing gland seals are used on what compressor?
Packing gland seals are used on what compressor?
a. Open type
b. Hermetic type
c. Large capacity ammonia compressor
d. Rotating sliding vane design
e....
Shaft seals are used on what compressor?
Shaft seals are used on what compressor?
a. Open type
b. Hermetic type
c. Stationary single-blade design
d. Rotating sliding vane design
e. Helical...
Advantages of the centrifugal compressor are?
Advantages of the centrifugal compressor are?
a. No moving parts
b. Can be coupled to an electric motor
c. Cheap
d. A and B
e. All of the above
Answer:...
Helical rotors revolve at speeds up to ___ r/min
Helical rotors revolve at speeds up to ___ r/min
a. 1550
b. 2550
c. 3550
d. 4550
e. 5550
Answer:...
Rotary compressor types are?i. Open typeii. Hermetic typeiii. Stationary single-blade designiv. Rotating sliding vane designv. Helical rotor design
a....
Reciprocating Compressor Types are? i. Open type ii. Hermetic type iii. Semihermetic type iv. Rotating sliding vane design v. Helical rotor design
Reciprocating Compressor Types are?i. Open typeii. Hermetic typeiii. Semihermetic typeiv. Rotating sliding vane designv. Helical rotor design
a....
Which of the following compressor types uses impellers to draw in vapour?
Which of the following compressor types uses impellers to draw in vapour?
a) Centrifugal compressors
b) Rotary compressors
c) Reciprocating Compressors
d)...
In a refrigeration system, the purpose of the compressor is to
In a refrigeration system, the purpose of the compressor is to
a) establish two pressure levels
b) reject the heat from the system
c) absorb the...
Which of the following is the compressor responsible for doing? i) Maintains a high pressure in the condenser ii) Maintains a low pressure in the evaporator iii) Raises the pressure of the refrigerant
Which of the following is the compressor responsible for doing?i) Maintains a high pressure in the condenserii) Maintains a low pressure in the evaporatoriii)...
Which of the following is not a function of the compressor in a refrigeration system?
Which of the following is not a function of the compressor in a refrigeration system?
a) draw low pressure refrigerant out of the evaporator
b) draw...
The pressure ratio of a refrigeration compressor can be calculated by dividing the:
The pressure ratio of a refrigeration compressor can be calculated by dividing the:
a. Discharge gage pressure by the inlet gage pressure
b. Swept...
Refrigerant compressors:
Refrigerant compressors:
a. Must have intercoolers
b. Could be centrifugal type
c. Use automotive-style suction and discharge valves
d. Have more...
In a sliding vane design refrigeration compressor, a good seal is maintained between the vanes and the cylinder by:
In a sliding vane design refrigeration compressor, a good seal is maintained between the vanes and the cylinder by:
a. Centrifugal force
b. Lube oil
c....
Which of the following is NOT a function of the refrigeration compressor?
Which of the following is NOT a function of the refrigeration compressor?
a. Raises the pressure of the refrigerant
b. Raises the temperature of...
A stationary crankshaft seal used on refrigeration compressors, which consists of a metallic bellows soldered at one end to a ring, and which presses against a shoulder on the shaft is called a:
A stationary crankshaft seal used on refrigeration compressors, which consists of a metallic bellows soldered at one end to a ring, and which presses...
For a Helical Rotor Design rotary refrigeration compressor, which of the following statements is true?
For a Helical Rotor Design rotary refrigeration compressor, which of the following statements is true?
a. The compressor consists of three opposing...
Which of the following is NOT considered a rotary refrigeration compressor design?
Which of the following is NOT considered a rotary refrigeration compressor design?
a. Screw
b. Sliding vane
c. Helical rotor
d. Centrifugal
e. Stationary...
A negative factor of Hermetic Type refrigeration compressors is:
A negative factor of Hermetic Type refrigeration compressors is:
a. They are too large to be used in any application except large industrial plants
b....
The safety head of a refrigeration compressor is designed to:
The safety head of a refrigeration compressor is designed to:
a. Unload over-loaded cylinders
b. Be installed on a hermetic compressor
c. Relieve...
Refrigerant compressors:
Refrigerant compressors:
a. Must have intercoolers
b. Could be centrifugal type
c. Use automotive-style suction and discharge valves
d. Have more...
The piston displacement of a reciprocating refrigeration compressor is defined as:
The piston displacement of a reciprocating refrigeration compressor is defined as:
a. The distance along which the piston travels
b. The cylinder...
A rotating mechanical seal, installed on a refrigeration compressor, is held in position by:
A rotating mechanical seal, installed on a refrigeration compressor, is held in position by:
a. The mating ring
b. Centrifugal force
c. The compressor...
The three main classifications of refrigeration compressors are:
The three main classifications of refrigeration compressors are:
a. Scroll, rotary, and positive displacement
b. Axial, centrifugal, and positive...
Refrigerant evaporators
Refrigerant evaporators
a) always have the refrigerant on the shell side
b) are located between the expansion valve and the receiver
c) may have...
Which of the following statements about a system that circulates warm brine or water back to a chiller tank is true?
Which of the following statements about a system that circulates warm brine or water back to a chiller tank is true?
a) The system is a direct refrigeration...
The primary difference between direct and indirect refrigeration systems is the
The primary difference between direct and indirect refrigeration systems is the
a) type of heat transfer medium
b) type of refrigerant
c) evaporator...
Which of the following are principal parts in a closed cycle compression refrigeration system? i) Absorber ii) Evaporator iii) Compressor iv) Condenser
Which of the following are principal parts in a closed cycle compression refrigeration system?i) Absorberii) Evaporatoriii) Compressoriv) Condenser
a)...
Choose the true statement. The economiser of a packaged water chiller, used for air conditioning, does NOT
Choose the true statement. The economiser of a packaged water chiller, used for air conditioning, does NOT
a. Have an intercooling effect on the compressor
b....
Which of the following is not an advantage of a factory assembled, packaged refrigeration unit?
Which of the following is not an advantage of a factory assembled, packaged refrigeration unit?
a. Components are designed to match each other
b....
In actual systems there will be a gradual pressure drop through each side of the system due to:
In actual systems there will be a gradual pressure drop through each side of the system due to:
a. Entropy
b. Friction in the evaporator, condenser,...
Which of the following is not a component of the low pressure side of a compression refrigeration system?
Which of the following is not a component of the low pressure side of a compression refrigeration system?
a. Compressor discharge piping
b. The...
The brine pump of a refrigeration system:
The brine pump of a refrigeration system:
a. Circulates the refrigerant through the evaporator
b. Pumps brine through the condenser cooling circuits
c....
In the evaporator of a refrigeration system:
In the evaporator of a refrigeration system:
a. The refrigerant rejects heat to the cooling tower
b. The refrigerant absorbs heat from the compressor...
In the condenser of a refrigeration system:
In the condenser of a refrigeration system:
a. Latent heat is restored to the refrigerant
b. The surrounding medium must be hotter than the refrigerant
c....
The temperature in the evaporator:
The temperature in the evaporator:
a. Depends on pressure in the receiver
b. Will decrease when the compressor stops
c. Depends on pressure in the...
With regard to economizers installed on packaged air-conditioning chillers, which of the following statements is false?
With regard to economizers installed on packaged air-conditioning chillers, which of the following statements is false?
a. Economizers control the...
Which of the following is not a component of a closed cycle compression refrigeration system?
Which of the following is not a component of a closed cycle compression refrigeration system?
a. Evaporator
b. Receiver
c. Compressor
d. Absorber
e....
For a direct expansion compression refrigeration system, which of the following statements is true?
For a direct expansion compression refrigeration system, which of the following statements is true?
a. The evaporator in this system is never in...
A compression refrigeration system can be divided into two parts; a high pressure section carrying the head pressure and a low pressure section carrying the _____ pressure:
A compression refrigeration system can be divided into two parts; a high pressure section carrying the head pressure and a low pressure section carrying...
Raising the condensing point (saturation temperature) of the refrigerant vapour above the temperature of the cooling medium is the function of the:
Raising the condensing point (saturation temperature) of the refrigerant vapour above the temperature of the cooling medium is the function of the:
a....
The type of brine used for skating and hockey rink refrigeration systems is usually:
The type of brine used for skating and hockey rink refrigeration systems is usually:
a. Calcium sulphate
b. Calcium chloride
c. Magnesium chloride
d....
In the condenser of a refrigeration system:
In the condenser of a refrigeration system:
a. Latent heat is restored to the refrigerant
b. The surrounding medium must be hotter than the refrigerant
c....
A purpose of a liquid refrigerant control or regulating valve (expansion valve)is to:
A purpose of a liquid refrigerant control or regulating valve (expansion valve)is to:
a. Drain the receiver
b. Regulate the refrigerant flow to the...
A controlled amount of high temperature, high pressure liquid refrigerant:
A controlled amount of high temperature, high pressure liquid refrigerant:
a. Passes through the regulating valve to the evaporator
b. Passes through...
A refrigeration system circulates warm brine back to a chiller. Which of the following statements about this system is true?
A refrigeration system circulates warm brine back to a chiller. Which of the following statements about this system is true?
a. The condenser in...
The enthalpy of a vapour is
The enthalpy of a vapour is
a. Sensible heat of a liquid
b. Sensible heat of a liquid plus latent heat of evaporation
c. Latent heat of evaporation
Answer:...
Ammonia is explosive in concentrations between?
Ammonia is explosive in concentrations between?
A. 5 to 10 %
b. 11 to 14 %
c. 16 to 25 %
d. 26 to 31 %
e. 32 to 40 %
Answer:...
Leakage tendency is determine by:
Leakage tendency is determine by:
a. Operating pressure
b. Viscosity
c. Density
d. Molecular mass
e. All of the above
Answer:...
The larger the difference between the temperature of the liquid refrigerant entering the evaporator and the actual evaporator temperature:
The larger the difference between the temperature of the liquid refrigerant entering the evaporator and the actual evaporator temperature:
a. The...
The amount of liquid that may flash into vapour can be as high as?
The amount of liquid that may flash into vapour can be as high as?
a. 30%
b. 40%
c. 50%
d. 60%
e. 70%
Answer:...
Which one of the following should a ideal refrigerant should NOT have?
Which one of the following should a ideal refrigerant should NOT have?
a. A low boiling point at atmospheric pressure
b. A high latent heat capacity:...
The refrigerant R-717 belongs to the following group
The refrigerant R-717 belongs to the following group
a) group "A2"
b) group "B1"
c) group "A3
d) group "B2"
e) group "A1"
Answer:...
The refrigerant R-764 belongs to the following group
The refrigerant R-764 belongs to the following group
a) group "A2"
b) group "B1"
c) group "A3
d) group "2B"
e) group "A1"
Answer:...
The refrigerant R-290 belongs to the following group
The refrigerant R-290 belongs to the following group
a) group "A2"
b) group "B1"
c) group "A3
d) group "2B"
e) group "A1"
Answer:...
The refrigerant R-600 belongs to the following group
The refrigerant R-600 belongs to the following group
a) group "A2"
b) group "B1"
c) group "A3
d) group "2B"
e) group "A1"
Answer:...
The refrigerant R-152a belongs to the following group
The refrigerant R-152a belongs to the following group
a) group "A2"
b) group "B1"
c) group "A3
d) group "2B"
e) group "A1"
Answer:...
The refrigerant R-142b belongs to the following group
The refrigerant R-142b belongs to the following group
a) group "A2"
b) group "B1"
c) group "A3
d) group "2B"
e) group "A1"
Answer:...
Ammonia is the only commonly used refrigerant which has the physical property of
Ammonia is the only commonly used refrigerant which has the physical property of
a) miscibility
b) enthalpy
c) flammability
d) density
e) low condensing...
Which of the following is not a physical property of refrigerants?
Which of the following is not a physical property of refrigerants?
a) Toxicity
b) Odour
c) Leakage tendency
d) Density
e) Explosiveness
Answer:...
The ability of a refrigerant to be dissolved into oil and vice versa is called
The ability of a refrigerant to be dissolved into oil and vice versa is called
a) moisture reaction
b) enthalpy
c) density
d) leakage tendency
e)...
Which of the following is a thermodynamic property of heat?
Which of the following is a thermodynamic property of heat?
a) entropy
b) enthalpy
c) density
d) volume
e) all of the above
Answer:...
The refrigerant R-11 belongs to the following group
The refrigerant R-11 belongs to the following group
a) group "A2"
b) group "B1"
c) group "A3
d) group "2B"
e) group "A1"
Answer:...
The molecular mass of a refrigerant is a factor in which of the following refrigerant characteristics?
The molecular mass of a refrigerant is a factor in which of the following refrigerant characteristics?
a. Miscibility
b. Leakage tendency
c. Toxicity
d....
The refrigerating effect of a refrigerant is:
The refrigerating effect of a refrigerant is:
a. Equal to its latent heat of vaporization
b. Greater than its latent heat of vaporization
c. Less...
R-134a is non-toxic and non-flammable. Which of the following groups does it belong to?
R-134a is non-toxic and non-flammable. Which of the following groups does it belong to?
a. Group A2
b. Group B4
c. Group A1
d. Group A3
e. Group B2
Answer:...
The property which has to be known for the calculation of the size of control valves and piping etc. is:
The property which has to be known for the calculation of the size of control valves and piping etc. is:
a. Specific gravity
b. Enthalpy
c. Refrigerating...
R-22:
R-22:
a. Is non-toxic
b. Has a strong, pungent odour
c. Is explosive when mixed with air
d. Is highly toxic
e. Is not an ozone-depleting substance
Answer:...
What is the name of the refrigerant that has the following characteristics? It is non-flammable, odourless, non-toxic, it does not have a corrosive effect on metal if water is present and at atmospheric pressure it has a boiling point of approximately -40.6°C.
What is the name of the refrigerant that has the following characteristics? It is non-flammable, odourless, non-toxic, it does not have a corrosive...
Which of the following characteristics is common in all of the group B refrigerants?
Which of the following characteristics is common in all of the group B refrigerants?
a. High toxicity
b. High flammability
c. Non-toxic but highly...
Group "A" refrigerants are:
Group "A" refrigerants are:
a. Non-flammable
b. Low-flammable
c. Low-toxic
d. Low-toxic and flammable
e. High-toxic and flammable
Answer:...
Which of the following has the highest boiling point at atmospheric pressure?
Which of the following has the highest boiling point at atmospheric pressure?
a. Ammonia
b. Freon 12
c. Freon 22
d. Freon 113
e. Water
Answer:...
The ideal refrigerant should:
The ideal refrigerant should:
a. Have a low latent heat capacity
b. Have a high boiling point
c. Have high condensing pressure
d. Be environmentally...
The latent heat of fusion of ice is:
The latent heat of fusion of ice is:
a. The sensible heat required for melting ice
b. 335 kJ per kg
c. 335 kJ per ton
d. The latent heat required...
The standard refrigeration cycle is used to compare refrigerants and machines operating under comparable conditions. These standard conditions are:
The standard refrigeration cycle is used to compare refrigerants and machines operating under comparable conditions. These standard conditions are:
a....
Which of the following is not a physical property of refrigerants
Which of the following is not a physical property of refrigerants
a. Toxicity
b. Odour
c. Leakage tendency
d. Corrosiveness
e. Miscibility
Answer:...
Ammonia, as well as being toxic, is also :
Ammonia, as well as being toxic, is also :
a. Miscible
b. Odourless
c. Flammable
d. Dense
e. A low pressure refrigerant
Answer:...
Ammonia refrigerants:
Ammonia refrigerants:
a. Have high sensible heat capacity
b. Mix well with oil
c. Are very expensive
d. Are well suited for industrial refrigeration
e....
A refrigerant in the "B" Group that is used more than others in its group in refrigeration systems is:
A refrigerant in the "B" Group that is used more than others in its group in refrigeration systems is:
a. R-290
b. Ammonia
c. R-134a
d. R-22
e. CO2
Answer:...
R-22 refrigerant is:
R-22 refrigerant is:
a. Not miscible with oil
b. Mostly used in packing plants
c. Corrosive on copper
d. Corrosive on aluminum
e. A heat transferring...
Refrigeration is usually measured in:
Refrigeration is usually measured in:
a. Kilojoules
b. Kilowatts
c. Tons
d. All the above
Answer:...
Superheat the evaporator is defined as:
Superheat the evaporator is defined as:
a. The most efficient way to remove heat from a process
b. The heat required to accelerate the cooling process
c....
The heat that a refrigerant absorbs to cause it to change from a liquid state to a gaseous state is called:
The heat that a refrigerant absorbs to cause it to change from a liquid state to a gaseous state is called:
a. Sensible heat
b. Convection
c. Latent...
Natural refrigeration is best described by the example of an:
Natural refrigeration is best described by the example of an:
a. Cooling fan
b. Outdoor rink
c. Ice box
d. Ceiling fan
Answer:...
Which column in the refrigerant table lists the absolute pressure in kPa?
Which column in the refrigerant table lists the absolute pressure in kPa?
a) Column 1
b) Column 2
c) Column 3
d) Column 4
e) None of the above
Answer:...
If a cooled medium had an evaporation temperature of 2 degrees C, the evaporation temperature of the liquid refrigerant should be approximately
If a cooled medium had an evaporation temperature of 2 degrees C, the evaporation temperature of the liquid refrigerant should be approximately
a)...
One tonne of refrigeration is
One tonne of refrigeration is
a) 13958 kJ per day
b) 100 kJ per minute
c) 233 kJ per minute
d) 13958 J per hour
e) 335 J per second
Answer:...
Refrigerant mediums will evaporate
Refrigerant mediums will evaporate
a) when pressure is increased
b) when temperature is increased
c) when they are diluted
d) when temperature is...
The rate at which a system will remove heat from the refrigerated medium is defined as
The rate at which a system will remove heat from the refrigerated medium is defined as
a) coefficient of performance
b) net refrigerating effect
c)...
Which of the following statements about high-side pressure and temperature is true?
Which of the following statements about high-side pressure and temperature is true?
a) The heat flow is from the cooling medium to the hot refrigerant.
b)...
Which of the following statements about low-side pressure and temperature is false?
Which of the following statements about low-side pressure and temperature is false?
a) The evaporation temperature of the refrigerant should be 5...
The function of the condenser is to
The function of the condenser is to
a) vaporize the liquid refrigerant
b) change high pressure refrigerant vapour to liquid
c) pressurize low pressure...
Which of the following is an example of a loss of latent heat? i) water evaporating ii) ice melting iii) refrigerant evaporating iv) air cooling
Which of the following is an example of a loss of latent heat?i) water evaporatingii) ice meltingiii) refrigerant evaporatingiv) air cooling
a) iv...
In the case of a simple ice box which of the following heat transfers is correct?
In the case of a simple ice box which of the following heat transfers is correct?
a) Air loses latent heat, ice does not gain any heat.
b) Air loses...
The net refrigerating effect of a refrigerant is the amount of heat:
The net refrigerating effect of a refrigerant is the amount of heat:
a. Discharged by the condenser
b. Absorbed by the refrigerant in the evaporator
c....
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