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SHELL AND TUBE HEAT EXCHANGER

AIM:

To determine the overall heat transfer co-efficient of the given shell and tube heat exchanger. To determine the effectiveness of the given heat exchanger.

INTRODUCTION:

Heat exchanger is process equipment designed for the effective heat transfer energy between two

fluids, hot and cold fluids.

Heat exchanger are classified into varying application .One of the fluid is carried through abundle of tubes enclosed by a shell and flows over the outside surface of the tubes .The direction of

flow for either or both fluid may change during its passages through the heat exchanger .Shell and tube

arrangement is used where heat transfer effectiveness of important with multi tubes .The surface area

is increased and to improve heat transfer rate.

FACTOR INFLUENCING:

Hot and cold fluid temperature Number of tubes of passes Direction of passes Flow rates Properties of fluids Material thickness

FORMULA:

[(Thi-Tci)-(Th0-Tc0)]

LMTD = ---------------------------

[ln[(Thi-Tci) (Th0-Tc0)]]

Where,

Thi initial temperature of hot fluid ( C )

Tcifinal temperature of cold fluid ( C )Th0initial temperature of hot fluid ( C )

Tc0 final temperature of cold fluid ( C )

Heat Capacity:

Qh = mh Cph(Thi-Th0)

Qc = mc Cpc (Tc0-Tci)

Qact= (Qh+Qc) / 2

Where,

mh mass flow rate of hot water ( kg / s )mc Mass flow rate of coldfluid ( kg / s )

cph,cpcs specific heat capacity of hot and cold fluid (kJ / kg K )

Overall heat transfer co-efficient:

U = Qact/ (ATm)

QactActual heat transfer rate

A heat transfer rate

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EFFFECTIVENESS:

Qact

E = -----------------------

C min (ThiTci)

Where,

cmin = mh cph or mc cpc

PROCEDURE:

Water was allowed to pass through the heater. The power supply was switched ON and arranging between 210 to 240 volts provided heat

to water which acts as a hot water inlet.

Flow rate of heat water and cold water are adjusted so that they both are same andmeasured using flash

Water was circulated until steady state was reached and the inlet and outlet temperaturewas noted.

Experiment was repeated for various flow rates.APPLICATION:

Used in direct on open heat exchanger using on open heat exchanger regenerator usingRecupurators,Boilers,Superheater,Condenser of power plant,Chemical processing

Industeries,Automobile Radiator etc..

Used for the Direction of motion, Parallel flow, counter flow, Cross flow and Mechanical flow.

SHELL AND TUBE HEAT EXCHANGER

S.N0HOT WATER

TEMPERATUE (C)COLD WATER

TEMPERATURE

(C)

TIME TAKEN

Thi Th0 Tci Tco Hot

water(ml)

Coldwater(ml)

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SHELL AND TUBE HEAT EXCHANGER

RESULTS:

For a given shell and tube type of heat exchanger

The overall heat transfer coefficient U=

Effectiveness of shell and tube heat exchanger E=

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