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European Journal of Business &

Social Sciences

Available at https://ejbss.org/

ISSN: 2235-767X

Volume 07 Issue 04

April 2019

Available online:https://ejbss.org/ P a g e | 1328

DESIGN AND ANALYSIS OF FAN ASSISTED

HEAT EXCHANGER

NATTAR RAJA .P

PG Student,

PRIST Deemed to be University, Thanjavur

Abstract – The present heat exchangers/radiators are

rectangular in shape. But the air blown by the fan is circular

in area, developing low velocity zones, high temperature

regions in the corners. Therefore temperature and velocity

readings are taken in all the four corners at various locations.

It is claimed that stagnation zones are created in the corners

and hence may be eliminated and proposed that the circular

radiators, if developed, will be optimum for improvement in

efficiency. Experimentation has been carried out by

considering temperature and velocity as variable, reveals that

low velocity zones along with high temperature regions (low

heat transfer zones) are developed as presumed in the

corners. The proposed design reduces/saves the material by

24%; cost saving on mass scale production will be about 20%

once the dies are manufactured.

Keywords- Heat exchanger, radiator, rectangular shape

I. Introduction

The proposed work relates to an improved heat

exchanger (Radiator) design for either heating or cooling

of a fluid. Also, it deals with the work particularly which

relates to an improved fan assisted air-cooled heat

exchanger used in Automobiles, Internal Combustion (IC)

engines, Refrigeration system, and Power plants. In the

race for manufacturing, everybody is working hard not

only to enhance quality, efficiency, performance of their

equipments but also to improve components including heat

exchangers.

Different types of heat exchangers are known, in which

air is used as heat transfer medium as it is freely and

abundantly available, without any disposal issues. In

known heat exchangers, flow of air is induced naturally or

is aided by the use of one or more fans. The use of fan

reduces the size and the cost of the equipment, which

makes it more compact. Hence, fan assisted air cooled heat

exchangers are more popular than others. In known air- cooled heat exchangers, the fan either forces or draws the

air through the heat exchanger, some of which are

described herein below by way of examples. In present

system, the fans are placed behind the heat exchangers to

force/ draw the atmospheric air. These exchangers use a

shroud. This directs the air over the entire area of the heat

exchanger.

Generally, all conventional heat exchangers are either square

or rectangular in shape and the fans with circular blades are

used to create the flow of air through them. During

combustion in the IC engines, temperature of hot gases in the

cylinder approaches to 2700 K. Such high temperatures are not

suitable for the proper working of the engine and have adverse

effects such as seizing of the piston- cylinder or damage to any

other engine parts. Hence the temperature has to be brought

down to 180-200 °C at which the engine will work efficiently.

Overcooling is also not desirable as it decreases the thermal

efficiency (ηth). Hence main aim of the cooling system is to

maintain the engine running at the most efficient operating

temperature. Fig.1 shows the schematic diagram of the liquid

cooling systems of a 4 –cylinder engine. It mainly consists of a

Radiator, Thermostat valve, Water pump, fan etc. Working of

the system is self explanatory. In the central section it consists

of a central radiator core. The upper section contains upper

tank and lower section contains lower tank.

Fig.1. Schematic Diagram of The Liquid Cooling Systems

II. Computational Fluid Dynamics Modeling

The commercial CFD Code Ansys Fluent was used

as preprocessor for solving the flow physics. The

computational Domain had to be represented as a finite