CPT CPT Heat Transfer & Thermodynamics 2

Question 1

What is 'latent heat' in the context of process thermodynamics?

Accepted Answer

Heat absorbed or released during a phase change at constant temperature

Answer

Latent heat is the energy absorbed or released when a substance changes phase (e.g., liquid to vapor) without a change in temperature.

Question 2

A steam trap in a process plant is used to:

Accepted Answer

Prevent steam from entering condensate return lines by discharging condensate while retaining steam

Answer

A steam trap automatically discharges liquid condensate and non-condensable gases from steam lines while preventing live steam from escaping, maintaining system efficiency.

Question 3

Fouling in a heat exchanger reduces its performance primarily by:

Accepted Answer

Adding thermal resistance that reduces the overall heat transfer coefficient

Answer

Scale, biological growth, or deposits on heat transfer surfaces act as insulating layers, increasing thermal resistance and lowering the effective heat transfer rate.

Question 4

What is the relationship between pressure and boiling point for water in a closed system?

Accepted Answer

Higher pressure raises the boiling point

Answer

In a closed system, increasing pressure requires more energy to convert liquid to vapor, raising the boiling point — this principle is used in pressure vessels and steam systems.

Question 5

Which instrument directly measures the enthalpy of steam entering a process unit?

Accepted Answer

Combined temperature and pressure measurement used with steam tables

Answer

Steam enthalpy is determined from steam tables using both measured temperature and pressure; neither reading alone is sufficient to determine the thermodynamic state.

(CPT) Certified Process Technician Practice Test

(CPT) Certified Process Technician Practice Test

CPT CPT Heat Transfer & Thermodynamics 2