JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisites

Advanced Heat and Mass Transfer

Course Objective

The course is intended to

• 1. Design and analyze the heat exchangers parallel flow, counter flow, multipass and, crossflow heat exchanger
• 2. Design and analyze the Shell and tube heat exchanger
• 3. Enable to carry out the performance of heat exchanger with the extended surfaces.
• 4. Design and analyze the cooling towers.

Course Outcomes

At the end of the course, the student will be able to:

• 1. Understand the physics and the mathematical treatment of typical heat exchangers.
• 2. Apply LMTD and Effectiveness methods in the design of heat exchangers and analyze theimportance of LMTD approach over AMTD approach.
• 3. Analyze the performance of double-pipe counter flow (hair-pin) heat exchangers.
• 4. Design and analyze the shell and tube heat exchanger.
• 5. Understand the fundamental, physical and mathematical aspects of boiling and condensation.
• 6. Classify cooling towers and explain their technical features.

UNIT - I

Classification of Heat Exchangers: Introduction, Recuperation & regeneration, Tabular heat exchangers, Double pipe, shell & tube heat exchanger, Plate heat Exchangers, Gasketed plate heat exchanger. Spiral plate heat exchanger, Lamella heat exchanger, Extended surface heat exchanger, Plate fin and Tubular fin. Basic Design Methods of Heat Exchanger: Introduction, Basic equations in design, Overall heat transfer coefficient, LMTD method for heat exchanger analysis, Parallel flow, Counter flow.Multipass, cross flow heat exchanger design calculations:

UNIT - II

Double Pipe Heat Exchanger: Film coefficient for fluids in annulus, fouling factors, Calorific temperature, Average fluid temperature, The calculation of double pipe exchanger, Double pipe exchangers in series parallel arrangements. Shell & Tube Heat Exchangers: Tube layouts for exchangers, Baffle heat exchangers, Calculation of shell and tube heat exchangers, Shell side film coefficients, Shell side equivalent diameter, The true temperature difference in a 1-2 heat exchanger. Influence of approach temperature on correction factor. Shell side pressure drop, Tube side pressure drop, Analysis of performance of 1-2 heat exchanger and design of shell & tube heat exchangers, Flow arrangements for increased heat recovery, the calculation of 2-4 exchangers.

UNIT - III

Condensation Of Single Vapours: Calculation of horizontal condenser, Vertical condenser, De-Super heater condenser, Vertical condenser- sub-Cooler, Horizontal Condenser- Sub cooler, Vertical reflux type condenser. Condensation of steam.

UNIT - IV

Vaporizers, Evaporators and Reboilers: Vaporizing processes, Forced circulation vaporizing exchanger, Natural circulation vaporizing exchangers, Calculations of a reboiler. Extended Surfaces: Longitudinal fins. Weighted fin efficiency curve, Calculation

of a Double pipe fin efficiency curve. Calculation of a double pipe finned exchanger, Calculation of a longitudinal fin shell and tube exchanger.

UNIT - V

Direct Contact Heat Exchangers, Heat pipe: Cooling towers, relation between wet bulb &dew bulb temperatures, calculation of cooling tower performance. Heat Pipe: Gravity assisted thermo-syphons, micro heat pipes, pulsating heat pipes, loop heat pipe operation & working principles.

TEXT BOOKS:

• 1. Process Heat Transfer by D.Q.Kern, TMH
• 2. Heat Exchanger Design by A.P.Fraas and M.N.Ozisick, John Wiely & sons, New York.

REFERENCE BOOKS:

• 1. Cooling Towers by J.D.Gurney and I.A. Cotter, Maclaren.
• 2. Heat Pipe Science & Technology, Amir Faghri, Taylor & Francis.
• 3. Heat Pipe Technology and Applications by J.P Peterson, John wiky & sons. M. TECH. II Year I Sem. (TE)