Solve this multiple-choice question and choose the correct option.

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Purpose of intercooling in multi-stage air compressors: choose the primary objective. Select the main reason intercoolers are used between compression stages.

Difficulty: Easy

To cool the air during compression
To cool the air at delivery
To enable compression in two stages
To minimise the work of compression

Correct Answer: To minimise the work of compression

Explanation:

Concept/ApproachFor a given overall pressure ratio, the compression work W ∝ ∫ v dp. Reducing the specific volume by cooling between stages lowers the required work.

Key resultPerfect intercooling (returning to the initial temperature) with equal pressure ratios per stage minimizes total work.

Final AnswerTo minimise the work of compression.

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