Tesztek

F-Gas English Low GWP

Minden kérdés
HFC | Flammable | CO₂ | NH₃
Könnyű kérdések | Közepes nehézségű kérdések | Nehéz kérdések

1

Könnyű


2

Könnyű

What is the base unit of mass in the International System of Units (SI)?


t
kg
lb (pound)
N

3

Könnyű

The refrigerant absorbs heat when…


…it freezes
…it evaporates
…it is subcooled
…it condenses

4

Könnyű

What does the GWP indicator mean?


The annual rise in mean air temperature caused by the emission of 1 kg of the gas
Ozone depletion potential
The ability of a substance to restore the ozone layer
Global Warming Potential: the climate warming impact of 1 kg of a gas compared with 1 kg of CO₂ (GWP = 1) over a defined time horizon, usually 100 years

5

Könnyű

What is the main function of a safety valve?


Prevents the evaporator from freezing
Discharges refrigerant when the set pressure is exceeded
It controls the oil level in the compressor
It monitors the moisture content of the refrigerant

6

Könnyű

What is the unit of pressure in the International System of Units (SI)?


Pa (pascal)
psi (pound per square inch)
atm (standard atmosphere)
bar (gauge)

7

Könnyű

What is the log(p)-h diagram for CO₂ used for?


To regulate pressure
For analysing thermodynamic processes in a refrigeration system
To detect leaks
To measure temperature

8

Könnyű

What can be read from the log(p)-h graph?


Only the amount of refrigerant
Only the humidity
Only the temperature
Pressure, enthalpy, temperature and state of the refrigerant

9

Könnyű

What are CO₂ saturation tables used for?


To regulate the compressor
To determine the relationship between temperature and pressure at saturation
To determine the oil quantity
To measure humidity

10

Könnyű

What does the CO₂ saturation state mean?


A state in which the refrigerant is only a gas
Equilibrium between the liquid and vapour phases
A state of high pressure
Dry ice state

11

Könnyű

Why is understanding the log(p)-h graph particularly important for CO₂?


It only applies to NH₃
As CO₂ systems operate in different modes (sub- and transcritical) and require detailed analysis
It doesn’t matter
It is only used for design purposes

12

Könnyű

Why do CO₂ systems require precise pressure control?


Because there are no valves
They do not require control
Due to significant pressure changes with temperature fluctuations
Due to low pressures

13

Könnyű

What is the basic requirement when charging a system with R717 (NH₃)?


Charging should take place in a well-ventilated area using appropriate personal protective equipment
NH₃ can be charged together with air
Charging can be carried out without personal protective equipment
Charging must only take place at temperatures below 0°C

14

Könnyű

What is the correct procedure for recovering R717 from a system?


The refrigerant can be drained into the sewer system
The gas can be released into the atmosphere
Recovery is not required
The refrigerant must be recovered into suitable, leak-proof tanks designed for NH₃

15

Könnyű

How should R717 (NH₃) be stored?


Near heat sources
In any open containers
In sealed, labelled containers, in a cool and well-ventilated place
In unmarked plastic containers

16

Könnyű

What is the main hazard associated with an R717 leak during maintenance work?


Increased cooling efficiency
Toxic to humans and may cause chemical burns
Damage to electrical equipment only
No risk whatsoever

17

Könnyű

What personal protective equipment is required when working with NH₃?


Only a safety helmet
Safety goggles, gloves and respiratory protective equipment
No requirements
Workwear only

18

Könnyű

How do system leaks affect compressor energy efficiency?


They improve efficiency because condensing pressure drops
Refrigerant loss reduces capacity and increases energy use (longer run times, higher superheat)
No effect as long as the system still cools
They affect only safety, not energy use

19

Könnyű

How does a dirty condenser affect the operation of the refrigeration system?


It lowers the condensing pressure
It improves efficiency
Causes an increase in pressure and energy consumption by the compressor
It has no effect

20

Könnyű

Why is adequate airflow through an air-cooled condenser important?


The lower the airflow, the lower the condensing pressure
It doesn't matter
It ensures effective heat rejection and low condensing pressure
It affects only noise

21

Könnyű

How does the presence of limescale in a water-cooled condenser affect performance?


It improves heat transfer
It has no effect
It lowers the condensation temperature
Impairs heat exchange and increases energy consumption

22

Könnyű

How do condenser leaks affect energy efficiency?


They lower the temperature
They improve efficiency
Have no effect
Causes refrigerant loss and a drop in efficiency

23

Könnyű

How important is the correct positioning of an air-cooled condenser?


It should be housed in a small room
It should be installed in a well-ventilated area with unobstructed airflow
It doesn’t matter
It should be close to heat sources

24

Könnyű

How does hot air recirculation affect the condenser?


Impairs cooling and increases energy consumption
It reduces the pressure
It has no effect
It improves efficiency

25

Könnyű

How does evaporator icing affect the system’s operation?


It has no effect
It improves cooling performance
It lowers the condensation temperature
Impairs heat exchange and increases energy consumption

26

Könnyű

How does dirt on the evaporator surface affect its performance?


It improves efficiency
It reduces the pressure
Impairs heat exchange and increases energy consumption
It has no effect

27

Könnyű

What maintenance task is crucial for the evaporator?


Reduced airflow
Lack of maintenance
Increasing the refrigerant charge
Regular cleaning and defrosting

28

Könnyű

How does superheat at the evaporator outlet affect efficiency?


It always improves performance
Excessive superheat reduces energy efficiency
It only causes a temperature drop
It has no effect

29

Könnyű

How do leaks in the evaporator affect efficiency?


Have no effect
Improves performance
Increase capacity
These cause refrigerant loss and a drop in efficiency

30

Könnyű

How important is correct expansion valve adjustment?


Causes leaks
Ensures optimal evaporator charge and improves efficiency
It increases energy consumption
It doesn’t matter

31

Könnyű

How does inadequate insulation of suction (or secondary-coolant) pipes affect evaporator performance?


It causes cooling losses and increased energy use
It has no effect
It improves efficiency
It lowers the condensing temperature

32

Könnyű

How does correct TEV adjustment affect system energy efficiency?


It ensures optimal superheat and improves efficiency
It has no effect
It causes leaks
It increases energy use

33

Könnyű

What happens if the superheat set by the TEV is too high?


Efficiency will drop because the evaporator is not being fully utilised
It has no effect
Cooling efficiency will improve
The refrigerant charge will increase

34

Könnyű

How do contaminants in the system affect the operation of the TEV?


They lower the temperature
Have no effect
They can cause it to become blocked and reduce efficiency
They improve its performance

35

Könnyű

What role does the filter-drier play in terms of system efficiency?


It doesn’t matter
It increases the amount of refrigerant
Removes moisture and contaminants, improving the system’s efficiency
It lowers the temperature

36

Könnyű

How does proper insulation of components (e.g. pipes near the TEV) affect the system?


It doesn’t matter
Prevents unwanted heat gains and improves efficiency
It increases energy consumption
It causes leaks

37

Könnyű

How important is it to check the operation of the condensing pressure control valve in the system?


Ensures operation within the optimum pressure range and reduces energy losses
It causes a significant rise in temperature
It increases energy consumption
It has no effect

38

Könnyű

How does the correct selection of a TEV affect energy efficiency?


Ensures the system is matched to its capacity and operates optimally
It increases the amount of refrigerant
It doesn’t matter
It lowers the temperature

39

Könnyű

What is the function of high-pressure control valves in CO₂ systems?


They are used to store the refrigerant
They lower the evaporator temperature
They control the pressure on the high-pressure side and optimise system operation
They regulate oil flow

40

Könnyű

Why do CO₂ systems require more advanced automation than traditional systems?


Due to low pressures
Because there are no valves
They do not require automation
Due to the need for precise control of pressure and temperature

41

Könnyű

What is the requirement regarding the labelling of an installation containing a flammable substance?


The labelling must indicate the type of substance and the flammability hazard
Labelling is required only in technical rooms
Colour-coding of pipes is sufficient
Labelling is not required for hermetically sealed systems

42

Könnyű

What are the potential consequences of using unsuitable connections in a system containing a flammable substance?


Merely a reduction in efficiency
No impact on safety
Risk of leakage and the formation of an explosive mixture
Merely installation difficulties

43

Könnyű

How should an employee respond when a gas alarm is triggered?


Carry on working until they see a leak
Reduce the pressure in the system
Leave the room immediately and notify their supervisor
Switch off the system and wait for the alarm to stop

44

Könnyű

Gas detectors should be installed in rooms where:


Ventilation is natural
The amount of refrigerant exceeds a specified permissible threshold
The room is less than 5 m²
Any refrigerant is present, regardless of the quantity

45

Könnyű

How do leaks affect systems using flammable refrigerants?


They improve efficiency
Have no effect
They cause refrigerant loss, reduced efficiency and a fire hazard
They lower the temperature

46

Könnyű

Why is the cleanliness of heat exchangers in HC systems important?


It improves heat transfer and reduces energy consumption
Causes leaks
It doesn’t matter
It increases the pressure

47

Könnyű

What maintenance measures improve the efficiency of a system using a flammable refrigerant?


Increasing the refrigerant charge
Disabling safety devices
Regular checks for leaks and operating parameters
Lack of servicing

48

Könnyű

How does the correct selection of components affect a system using a flammable refrigerant?


It lowers the temperature
It increases the amount of refrigerant
It doesn’t matter
It ensures safe and optimal operation and minimises energy losses

49

Könnyű

Why is it important to use the correct service tools in HC systems?


Causes leaks
It increases energy consumption
It doesn’t matter
It ensures operational safety and reduces refrigerant losses

50

Könnyű

How does pipe insulation affect the efficiency of systems containing HC?


It reduces energy losses and improves efficiency
It doesn’t matter
Causes leaks
It increases the pressure

51

Könnyű

What is the base unit of temperature according to the International System of Units (Système International d’Unités)?


K
°C
°F
°R

52

Könnyű

What is the superheat of refrigerant vapour?


The difference between the actual vapour temperature and the saturation temperature corresponding to its pressure (expressed in K)
The difference between the condensing temperature and the ambient temperature
The difference between the saturation temperature and the actual liquid temperature in the liquid line
The amount of heat required to evaporate a liquid

53

Könnyű

What is the compression ratio of a compressor?


The ratio of suction pressure to discharge pressure (po/pc)
The ratio of discharge pressure to the effective capacity of the compressor (p/Vk)
The amount of refrigerant compressed per cycle relative to heat capacity
The ratio of absolute discharge pressure to absolute suction pressure (pc/po)

54

Könnyű

What is the theoretical displacement (swept volume flow) of a compressor?


The volume of vapour drawn in per unit of time, determined by the compressor's geometry and speed (stated by the manufacturer, e.g. in m³/h)
A value expressed by the coefficient of performance (COP)
The volume of a single cylinder in cm³
The volume of refrigerant flowing in one piston cycle under actual operating conditions

55

Könnyű

What is the clearance (dead) volume of a reciprocating compressor?


The space between the side of the piston and the cylinder
The space between the underside of the piston and the crankcase cover
The volume between the valve plate and the piston crown at top dead centre
The volume between the valve plate and the piston at bottom dead centre