Steam engine valve losses: initial cylinder pressure vs. boiler pressure At the beginning of the piston stroke, how does the cylinder steam pressure compare with the boiler pressure (considering throttling and valve losses)? Choose the correct relation.
Mechanical Engineering
Steam Boilers and Engines
Difficulty: Easy
Choose an option
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AEqual to the boiler pressure
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BLess than the boiler pressure
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CGreater than the boiler pressure
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DIndeterminate/always variable
Answer
Correct Answer: Less than the boiler pressure
Explanation
ConceptDue to throttling across ports/valves and pressure drops in the steam pipe, the initial admission pressure in the cylinder is lower than the boiler pressure in practical engines.
Final AnswerLess than the boiler pressure