Definition check – What is a heat exchanger? Confirm whether the statement “A device used for transferring heat from one fluid to another” correctly defines a heat exchanger.
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ATrue
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BFalse
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CTrue only if fluids are in direct contact
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DTrue only if phase change occurs
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ETrue only for counter-flow devices
Answer
Correct Answer: True
Explanation
Introduction / Context:Heat exchangers are ubiquitous in HVAC, power, chemical processing, and refrigeration. A clear definition underpins proper selection among shell-and-tube, plate-and-frame, finned-tube, condensers, evaporators, and regenerative devices.
Given Data / Assumptions:
- Two or more fluids at different temperatures exchange heat.
- Heat transfer may be with or without phase change (sensible or latent).
- Fluids can be kept separate (indirect contact) or mixed (direct contact towers).
Concept / Approach:A heat exchanger is any device facilitating heat transfer between fluids separated by a wall (indirect contact) or in direct contact without significant external work. The definition does not mandate a particular flow arrangement or phase change.
Step-by-Step Solution:Match the statement to standard definitions.Recognize inclusivity: condensers, evaporators, economizers, oil coolers, air heaters, and cooling towers fit.Therefore the statement is correct.
Verification / Alternative check:Texts define heat exchangers broadly; specialized names (condenser, boiler) are specific applications but still heat exchangers by function.
Why Other Options Are Wrong:
- Limiting to direct contact, requiring phase change, or restricting to counter-flow excludes many legitimate devices.
Common Pitfalls:Equating “heat exchanger” only with shell-and-tube; forgetting that regenerative and recuperative devices are included; mixing “heater” and “exchanger” terminology.
Final Answer:True