NEW
Font size
WorksheetsBSE UNIT 12 LESSON 8 Refrigeration Systems Quiz
Total questions: 60
Worksheet time: 30mins
What should learners be able to describe by the end of the session?
The principle of the heat pump cycle
The principle of the vapour compression cycle
The components of a heating system
The layout of a heating plant
Which of the following is one of the session objectives for learners?
Sketch the layout of a heating system plant
List the main components in a vapour compression system
Discuss the principles of solar panel installation
Explain the workings of a geothermal heating system
What principle related to air systems using refrigeration should learners be able to explain?
The principle of humidity control
The principle of heat recovery
The principle of air purification
The principle of air circulation
What are learners expected to sketch by the end of the session?
The layout of a solar power system plant
The layout of a chilled water system plant
The layout of a wind energy system plant
The layout of a hydroelectric power system plant
What topic regarding refrigeration systems should learners be able to discuss?
The environmental impact
The cost-effectiveness
The advantages and disadvantages
The energy efficiency standards
Why are natural refrigerants like hydrocarbons considered highly reliable for refrigeration systems?
They are less expensive than synthetic refrigerants.
They have lower running costs for refrigeration units.
They don't deplete the ozone layer.
They reduce the risk of fire from leakages.
What is one of the environmental downsides of refrigeration units that are not economically repairable?
They increase the risk of fire hazards.
They contribute to ozone layer depletion.
They lead to an increased amount of waste due to replacement.
They are more expensive to operate than new units.
What is a disadvantage of using air as a refrigerant in terms of operational costs?
It has a high fire risk.
It is not readily available.
It has high running costs.
It contributes to pollutant contamination.
What is a characteristic of a chemical that qualifies it as a refrigerant according to the text?
It has unfavourable thermodynamic properties.
It is corrosive to mechanical components.
It contributes to climate change.
It has favourable thermodynamic properties.
Which of the following is NOT a requirement for refrigerants as mentioned in the text?
Non-corrosive to mechanical components
Safe and non-toxic
High flammability
Does not contribute to ozone depletion
What are the desired thermodynamic properties of a refrigerant?
High boiling point and low heat of vaporisation
Low density in both liquid and gaseous form
Boiling point below the target temperature and high heat of vaporisation
Contributes to ozone depletion
How can refrigerants be made more suitable for a particular application?
By changing their chemical composition
By choosing appropriate operating pressures
By increasing their toxicity
By making them corrosive
What is the vapour compression cycle a thermodynamic process used for in refrigeration systems?
To transfer heat from one environment to another
To generate electricity
To purify water
To compress air for industrial use
Which process is NOT part of the vapour compression cycle?
Compression
Condensation
Expansion
Filtration
During the vapour compression cycle, what is the refrigerant subjected to after cooling?
Expansion
Heating
Compression
Solidification
What is the result of the refrigerant heating process in the vapour compression cycle?
Condensation
Evaporation
Sublimation
Freezing
What is the function of the evaporator in the vapour compression cycle?
It increases the gas pressure and elevates the heat capacity of the gas.
It causes heat to be rejected by the gas which changes back to a liquid.
It has a cooling effect where heat is absorbed by the refrigerant to phase change to gas.
It increases the liquid volume and reduces its pressure and heat capacity.
What does the compressor do in the vapour compression cycle?
It causes heat to be rejected by the gas which changes back to a liquid.
It has a cooling effect where heat is absorbed by the refrigerant to phase change to gas.
It increases the liquid volume and reduces its pressure and heat capacity.
It increases the gas pressure and elevates the heat capacity of the gas.
What is the role of the condenser in the vapour compression cycle?
It increases the gas pressure and elevates the heat capacity of the gas.
It has a cooling effect where heat is absorbed by the refrigerant to phase change to gas.
It causes heat to be rejected by the gas which changes back to a liquid.
It increases the liquid volume and reduces its pressure and heat capacity.
What effect does expansion have in the vapour compression cycle?
It increases the gas pressure and elevates the heat capacity of the gas.
It causes heat to be rejected by the gas which changes back to a liquid.
It has a cooling effect where heat is absorbed by the refrigerant to phase change to gas.
It increases the liquid volume and therefore reduces its pressure and its heat capacity.
What happens to the refrigerant during the evaporation process in a compression cycle?
The refrigerant is condensed into a liquid.
The refrigerant is effectively boiled into a gaseous phase.
The refrigerant is passed through a compressor.
The refrigerant remains in a liquid state.
Where is heat rejected in the condensation process of a compression cycle?
In the compressor
In the expansion valve
In the heat exchanger
In the evaporator
What indicates the efficiency of the system in a compression cycle?
The temperature of the refrigerant
The pressure of the refrigerant
The difference between heat absorption and rejection
The phase change of the refrigerant
What type of pipe material is generally used for system pipework in the installation of a refrigeration system?
PVC pipe
Copper coiled pipe
Stainless steel pipe
Flexible plastic tubing
What is used to purge completed pipework to prevent internal oxygenising when joins are brazed?
Compressed air
Oxygen free nitrogen
Carbon dioxide
Water vapor
What is created in the system before it is filled with refrigerant gas/liquid?
Pressure
A vacuum
Moisture
Heat
What type of testing is performed to ensure no atmospheric pollution of refrigerant gas?
Efficiency testing
Tightness testing
Performance testing
Safety testing
After Brexit, to which regulation do permissible refrigerant gases in Great Britain broadly adhere?
EU F-GAS Regulation 2015
EU F-GAS Regulation 2018
EU F-GAS Regulation 2020
EU F-GAS Regulation 2022
Where is a hermetically sealed compressor typically found?
In automotive air conditioning systems
In domestic refrigerators and freezers
In commercial heating systems
In industrial ventilation units
What makes a hermetically sealed compressor ready for installation?
It is charged with refrigerant
It comes with an instruction manual
It is manufactured with a factory sealed vacuum
It includes mounting hardware
Compared to hermetically sealed compressors, industrial compressors are:
Simpler in design
Less commonly used
More complex in their constituent parts
Always smaller in size
What is the function of the component labeled "Reversible positive displacement oil pump" in an industrial refrigerant compressor?
To compress the refrigerant gas
To provide lubrication throughout the compressor
To release excess pressure from the compressor
To convert electrical energy into mechanical energy
Which component in the industrial refrigerant compressor is responsible for compressing the refrigerant gas?
Connecting rod
Discharge valve relief spring assembly
Pistons
Crankshaft seal assembly
What is the purpose of the "Crankshaft seal assembly" in an industrial refrigerant compressor?
To ensure the pistons move smoothly
To maintain pressure within the cylinders
To prevent refrigerant leakage along the crankshaft
To connect the pistons to the crankshaft
What is the function of the expansion valve in a refrigeration system?
To increase the pressure of the refrigerant
To restrict the flow of refrigerant entering the evaporator
To compress the refrigerant into a liquid form
To absorb heat from the refrigerant
What happens to the refrigerant when it passes through the expansion valve?
It becomes a high pressure liquid
It is heated up by the sensing bulb
Its pressure and volume decrease
Its pressure is reduced and volume expands
What is connected to the expansion valve via a capillary tube?
A compressor
A condenser
A sensing bulb
An evaporator
What does the sensing bulb measure in the refrigeration system?
The volume of the refrigerant
The pressure of the refrigerant
Small differences in temperature
The velocity of the refrigerant
Where is the sensing bulb attached in relation to the evaporator?
To the inlet tube of the evaporator
To the outlet tube of the evaporator heat exchanger
Inside the evaporator coils
To the exterior of the evaporator casing
What is the function of the external equalisation connection in a refrigerant expansion valve?
It senses the temperature of the refrigerant.
It adjusts the superheat of the refrigerant.
It connects the valve to the evaporator.
It balances the pressure between the valve and the evaporator outlet.
Where is the sensing bulb of a refrigerant expansion valve typically located?
At the inlet of the condenser.
At the outlet of the evaporator.
Inside the poppet valve.
Attached to the external equalisation connection.
What is the purpose of the superheat adjustment spring in a refrigerant expansion valve?
To control the flow of refrigerant into the evaporator.
To measure the temperature of the refrigerant.
To maintain the pressure within the condenser.
To regulate the defrost cycle of the refrigeration system.
What type of motor does a reciprocating chiller use to drive compressor pistons?
Hydraulic motor
Electric motor
Pneumatic motor
Diesel motor
What are the two main components of a reciprocating chiller where heat exchange occurs?
Condenser and evaporator
Compressor and expansion valve
Expansion valve and condenser
Compressor and evaporator
What is the approximate temperature of the chilled water leaving the evaporator in a reciprocating chiller?
0°C
7°C
70°C
100°C
What type of flow operation is usually found in the shell and tube calorifiers of a reciprocating chiller?
Parallel flow
Crossflow
Counterflow
Direct flow
What is the purpose of having a buffer tank in a chilled water system?
To increase the pressure of the system
To cater for fluctuations in demand
To purify the chilled water
To cool down the water before it enters the evaporator
Where is the chilled water fed to in a chilled water system?
Directly back to the feed cistern
To the AC handling plant or individual air handling unit
Into the cooling tower
Through the water make-up line
What is the effectiveness of refrigeration cycles in AC systems for performing heat recovery from one air source to another?
Up to 26% of heat can be recovered
Up to 36% of heat can be recovered
Up to 46% of heat can be recovered
Up to 56% of heat can be recovered
What feature of AC systems allows them to have winter and summer modes?
Reversible water compression and a runaround coil
Reversible vapour compression and a runaround coil
Irreversible vapour compression and a runaround coil
Reversible vapour compression and a fixed coil
Which systems were discussed in Session 1 that the text refers to?
Central plant, constant and variable air volume systems
Central heating, constant and variable air pressure systems
Peripheral plant, constant and variable air volume systems
Central plant, constant and variable air velocity systems
What does VRV stand for in the context of AC systems?
Variable refrigerant volume
Variable refrigerant velocity
Variable return volume
Variable resistance volume
What is the function of the component labeled "Expansion valve" in the DX refrigerant runaround coil system (winter mode)?
To compress the refrigerant
To cool the supply air
To expand the refrigerant and reduce its pressure
To heat the exhaust air
In the DX refrigerant runaround coil system (winter mode), what is the function of the "Heating coil (condenser)"?
To absorb heat from the exhaust air
To release heat to the supply air
To compress the refrigerant
To expand the refrigerant
Which component in the DX refrigerant runaround coil system (winter mode) is responsible for increasing the pressure of the refrigerant?
Expansion valve
Heating coil (condenser)
Compressor
Cooling coil (evaporator)
What is the role of the "Cooling coil (evaporator)" in the DX refrigerant runaround coil system during winter mode?
To heat the refrigerant
To cool the exhaust air
To compress the refrigerant
To absorb heat from the supply air
What is the function of the component labeled "Expansion valve" in the DX refrigerant runaround coil system (summer mode)?
To compress the refrigerant
To release exhaust air
To expand and cool the refrigerant
To heat the refrigerant
In the DX refrigerant runaround coil system (summer mode), what is the role of the "Compressor"?
To expand and cool the refrigerant
To compress the refrigerant
To release supply air
To control the flow of refrigerant
Which component in the DX refrigerant runaround coil system (summer mode) is responsible for releasing the heat absorbed from the supply air?
Cooling coil (evaporator)
Expansion valve
Heating coil (condenser)
Compressor
What is the purpose of the "Cooling coil (evaporator)" in the DX refrigerant runaround coil system during summer mode?
To heat the refrigerant
To compress the refrigerant
To absorb heat from the supply air
To release exhaust air
