Boiler performance definitions — check the statement Is the following statement correct? “The ratio of heat actually used in producing the steam to the heat liberated in the furnace is known as equivalent evaporation from and at 100°C.”

Introduction / Context:
Boiler performance uses several related terms—boiler efficiency, evaporation ratio, equivalent evaporation, and factor of evaporation. Mislabeling these can lead to wrong interpretations of tests and guarantees. This question asks you to validate a specific definition.

Given Data / Assumptions:

• Heat balance across the boiler is well defined.
• Reference condition “from and at 100°C” is understood for equivalent evaporation.

Concept / Approach:
The ratio of useful heat added to the water/steam to the heat released by fuel is boiler efficiency. Equivalent evaporation is a different concept: it is the amount of water that would be evaporated from and at 100°C per unit time corresponding to the same heat transfer actually achieved. Hence, the statement equating the efficiency ratio to equivalent evaporation is incorrect.

Step-by-Step Solution:

Verification / Alternative check:
Acceptance codes and textbooks consistently distinguish between η_b (dimensionless) and equivalent evaporation (kg/h or kg/s).

Why Other Options Are Wrong:

• “Correct” and other qualified variants: conflate two distinct quantities—one is a ratio, the other is a standardized mass flow.

Common Pitfalls:
Using equivalent evaporation as a percentage; ignoring superheat/unevaporated sensible heating when converting to equivalent terms.

Final Answer: