Boiler performance terminology — choose the correct definition Is the following statement correct? “The amount of water evaporated from and at 100°C into dry saturated steam is called the evaporative capacity of a boiler.”

Introduction / Context:
In boiler testing and performance comparison, two closely related terms are frequently confused: “evaporative capacity” and “equivalent evaporation from and at 100°C.” The wording in the prompt deliberately mixes them. This question checks whether you can distinguish the everyday capacity rating (actual kg/h produced under given conditions) from the standardized reference basis used for fair comparisons across different operating pressures and feedwater temperatures.

Given Data / Assumptions:

• “From and at 100°C” refers to water at 100°C being converted to dry saturated steam at 100°C (atmospheric pressure).
• Evaporative capacity refers to the actual mass of steam generated per hour under the boiler’s working conditions.
• Standard practice uses a conversion via the factor of evaporation to express results on the “from and at 100°C” basis.

Concept / Approach:
Equivalent evaporation (EE) is a normalization concept. It answers: “If the same amount of heat that the boiler actually delivered were applied at the 100°C reference, how many kilograms would be evaporated per hour?” The evaporative capacity, by contrast, is the real, on-site steam production (kg/h) at the actual pressure, temperature, and feedwater conditions. Therefore, saying “from and at 100°C” defines equivalent evaporation, not evaporative capacity.

Step-by-Step Solution:
Define EE: EE = (actual enthalpy rise per kg) / (latent heat at 100°C).Define capacity: Capacity = actual steam flow rate (kg/h) delivered by the boiler.Compare definitions: “from and at 100°C” belongs to EE, not capacity.Hence, the statement is incorrect.

Verification / Alternative check:
In boiler trials, measured feedwater flow is multiplied by the factor of evaporation to convert to equivalent evaporation. Nameplates often quote both actual capacity (kg/h) and equivalent evaporation for marketing comparability.

Why Other Options Are Wrong:

• Yes/conditional answers confuse the standardized basis with real operating output.
• Dependence on feedwater temperature is handled via the factor of evaporation, not by redefining capacity.

Common Pitfalls:
Assuming “from and at 100°C” is a generic phrase for any boiler output. It is strictly the reference-basis term equivalent evaporation.

Final Answer:
No