F-Gas English Low GWP

All questions
HFC | Flammable | CO₂ | NH₃
Easy questions | Medium questions | Difficult questions

1

Easy

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


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

2

Easy

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


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

3

Easy

What are CO₂ saturation tables used for?


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

4

Easy

What does the CO₂ saturation state mean?


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

5

Easy

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


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

6

Easy

Why do CO₂ systems require precise pressure control?


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

7

Easy

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


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

8

Easy

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


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