Definition check — simple steam engine: Is the statement correct? “If steam expands in a single cylinder and then exhausts to atmosphere or to a condenser, the engine is called a simple steam engine.”
-
ACorrect
-
BIncorrect
-
CCorrect only if non-condensing
-
DCorrect only if condensing
-
ECorrect only with throttling control
Answer
Correct Answer: Correct
Explanation
Introduction:Engine taxonomy distinguishes between simple (single-expansion) and compound (multi-expansion) machines. The definition does not depend on whether the exhaust discharges to atmosphere or to a condenser; it hinges on how many cylinders perform the expansion work.Given Data / Assumptions:
- Single expansion stage in one cylinder.
- Exhaust may be non-condensing (to atmosphere) or condensing (to vacuum).
Concept / Approach:A simple steam engine completes the entire steam expansion in one cylinder. A compound or multiple-expansion engine distributes expansion over two or more cylinders. The presence of a condenser merely changes back pressure and efficiency; it does not change the “simple” classification if expansion still occurs in a single cylinder.
Step-by-Step Solution:
Check number of expansion cylinders: one ⇒ simple.Exhaust path: atmosphere or condenser, both allowed under “simple.”Therefore, the provided statement is correct.Verification / Alternative check:Classic texts list “simple non-condensing” and “simple condensing” as two subtypes within the simple engine category.
Why Other Options Are Wrong:
- Incorrect: conflicts with standard classification.
- “Only if non-condensing/condensing”: exhaust destination does not define “simple.”
- “Only with throttling”: governor method is independent of the simple/compound distinction.
Common Pitfalls:Equating condenser presence with compounding; the condenser affects back pressure, not expansion staging.
Final Answer:
Correct