1 Heat Exchangers Types & Applications, LMTD Derivation & problems
2 Heat Exchangers A heat exchanger is defined as an equipment which transfers the heat from a hot fluid to a cold fluid. Definition Types of heat exchangers: Criteria for classification of heat exchangers: (i) Nature of heat exchange process (ii) Relative direction of fluid motion (iii) Design and constructional features (iv) Physical state of fluids I. Nature of heat exchange process: a) Direct contact heat exchangers or Open heat exchangers Examples: Cooling towers, Direct contact feed heaters b) Indirect contact heat exchangers. Examples: IC engines, gas turbines, Air pre heaters, Economisers.
3 HEAT EXCHANGERS II. Relative direction of fluid motion: a. Parallel flow heat exchanger – Fluids move in same direction b. Counter flow heat exchanger – Fluids move in opposite direction c. Cross flow heat exchanger – Fluids make right angle to each other III. Design and constructional features: a. Concentric tubes b. Shell and tube (most widely used) c. Multiple shell and tube passes d. Compact heat exchangers IV. Physical state of fluids: a. Condensers b. Evaporators .
4 HEAT EXCHANGERS • Automobiles (Radiators, Air preheater, Exhaust gas heat removal) •
You've reached the end of your free preview.
Want to read all 11 pages?
- Spring '20
- Heat Transfer, dt, Log mean temperature difference