Applications of heat exchangers Identify where heat exchangers are commonly used in thermal engineering practice.

Introduction / Context:
Heat exchangers enable energy transfer between two fluids at different temperatures without direct mixing. They are foundational components across power, process, automotive, and HVAC industries. Recognizing their ubiquitous applications helps connect theory with real systems.

Given Data / Assumptions:

• Two-stream heat exchangers with metal walls separating fluids.
• Steady operation and typical industrial configurations.
• Focus on application domains rather than specific designs.

Concept / Approach:
In automobiles, the engine radiator rejects heat from coolant to air. In steam plants, boilers transfer heat from combustion gases to water/steam, and condensers remove latent heat from exhaust steam to cooling water. In refrigeration and air conditioning, evaporators absorb heat from the conditioned space while condensers reject heat to ambient. Each is a heat exchanger performing sensible or latent heat transfer (or both).

Step-by-Step Solution:

Verification / Alternative check:
System schematics across these industries prominently display heat exchangers labeled as radiators, condensers, boilers, economizers, intercoolers, and aftercoolers—substantiating the wide applicability.

Why Other Options Are Wrong:

Choosing any single application ignores the prevalence of heat exchangers elsewhere.“Only in power plants” is clearly false due to automotive and HVAC usage.

Common Pitfalls:
Assuming the term “boiler” is separate from heat exchangers; a boiler is a specialized heat exchanger producing phase change on the water side with combustion products on the hot side.

Final Answer:

All of the above