Defining a “Good” Steam Boiler — Steam Output for Given Fuel State whether the following statement is accurate: “A good steam boiler is one which produces the maximum quantity of steam for a given amount of fuel.”

Introduction:
At its core, boiler performance is about converting fuel energy into steam energy efficiently and reliably. A concise way to express this is to maximize steam output (or heat to steam) per unit of fuel, which correlates with high thermal efficiency and effective heat recovery.

Given Data / Assumptions:

• Comparable steam conditions (pressure/temperature) when comparing outputs.
• Boiler operates safely within design limits.
• Quality of steam (dryness/superheat) is maintained.

Concept / Approach:
For a fixed fuel input, higher useful heat absorbed by water/steam means higher efficiency. Practical designs achieve this via adequate heating surface, good circulation, low excess air, economisers/air preheaters, and minimized stack and radiation losses. Thus, “maximum steam for given fuel” sensibly captures efficiency as a key attribute of a “good” boiler.

Step-by-Step Solution:
Tie statement to efficiency: η_boiler ≈ useful heat to steam / fuel heat input.For constant firing rate, larger useful heat implies more steam generation.Therefore, the statement aligns with maximizing η and is acceptable.

Verification / Alternative check:
Heat balance diagrams show that reducing stack temperature and optimizing excess air directly increase steam generation per unit of fuel, supporting the definition.

Why Other Options Are Wrong:

• Disagree: would imply efficiency is not a primary measure, which contradicts standard practice.
• Load- or fuel-specific qualifiers are unnecessary; the principle applies broadly.

Common Pitfalls:
Ignoring steam condition differences; equal kilograms of low-pressure saturated steam are not energetically identical to high-pressure superheated steam—comparisons must be like-for-like.

Final Answer:
Agree