Experimental Performance Analysis of Flow of Air Curtain

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International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976

6340(Print), ISSN 0976 6359(Online) Volume 4, Issue 3, May - June (2013) IAEME

79

EXPERIMENTAL PERFORMANCE ANALYSIS OF FLOW OF AIR

CURTAIN

Mr Nitin Kardekar1,Dr. V K Bhojwani

2, Dr Sane N K

3

1Principal, Jayawantrao Sawant Polytechnic.Research Scholar, Singhania University

2Professor JSPMs Jayawantrao Sawant College of Engineering, Pune

3Research Supervisor, Singhania University

ABSTRACT

A study is undertaken to establish a relation between the power consumed by air

curtain and the performance of air curtain in terms of discharge air velocity from it. The

prototype experimental set up is established in the laboratory. The series of observations are

made by varying the input voltage and its effect on the output air velocity of the air curtain.

The air velocity forms the invisible barrier of air in the form of curtain which separates the

conditioned and unconditioned environments. The results are displayed in the form of graph.

The graphs are analysed in the light of actual performance and conclusions are drawn from

the study. The study reveals that there is great scope of savings in power consumption by

making small changes in the design of air curtain.

Keywords: air curtain, discharge air velocity, performance of air curtain, power consumption

of air curtain, effectiveness of air curtain.

INTRODUCTION

For the study and analysis of the performance of air curtain, the application chosen is

door way air curtain. The door way air curtains are extensively used in shopping malls,

banks, retail shop etc. The purpose is to restrict the cold/hot air loss from conditioned space

by installing the air barrier. An air curtain device also helps in prevention of dust, dirt or

insects entering in to conditioned spaces. Air curtains are also finding applications in

avoiding smoke propagation, biological controls and explosive detection portals. According

to research by US department of energy, 1875MW energy will be saved per year if super

market display cabinet air curtain will be operated at optimised performance [4] In 2002 the

INTERNATIONAL JOURNAL OF MECHANICAL ENGINEERINGAND TECHNOLOGY (IJMET)

ISSN 0976 6340 (Print)

ISSN 0976 6359 (Online)

Volume 4, Issue 3, May - June (2013), pp. 79-84

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UK food and drinks industryused equivalent of 285 tonnes of oil to power its refrigeration

industry, with most being used in cold storage. In developing countries like India; the rise in

cold storages, super markets, retail stores, banks are not only limited to mega cities but they

have also become the integral part of suburbans and small towns. The effects ofglobalisation are inevitable. The air curtains are no more luxury but are the necessary part of

business development and economy. Hence the study of air curtain with respect to Indian

climate is utmost necessary to ensure optimised performance of air curtains which will lead to

energy conservation. The saving of energy (Electrical energy) will always be boon for energy

starving country like India.

METHODOLOGY

The Technocrat make air curtain for door size W 950 mm X H 2530 mm Model 3

ft. HV+ Beta is chosen for the analysis purpose. As shown in Figure 1 the prototype of door

way is manufactured with help of plywood which is supported by MS angle frame. The air

curtain is mounted on the door way. The flow straightener is added in order to reduce theturbulences in the air flow.In order to reduce direct interference of the suction head of the air

curtain, the suction duct is added as shown in Figure 1. The length of the Suction head is kept

1000 mm from the end of the air curtain device. The power cord of air curtain is connected to

mains through the dimmer stat. Dimmer stat helps in the variation of input voltage to the air

curtain device. The voltage change will change the output of dual motor (i.e. speed of the

shaft). This results in variations of output air velocity of air curtain device. The air velocity in

air curtains is a very important parameter impacting its effectiveness. The input voltage to fan

motor is measured by digital multi meter. The power supplied to air curtain is measured by

the watt meter. In order to measure the air velocity at fixed points, a grid of the thread is

placed in air flow path of air curtain. This facilitates to measure the velocity of air flow of air

curtain when input parameters are varied. With help of grid it is easy to find the location of

point in the space for measurement of velocity at different input voltages. The input voltage isvaried from 125 V to 225 V with increment of 25 Volts. The speed of the fan is measured

using digital Tachometer and the velocity is measured using digital anemometer. All the

instruments are calibrated before use. The entire experimentation is carried out at isothermal

conditions; ambient air at 240C ( + 1

0C) at one atmosphere.

RESULT AND DISCUSSION

The prototype experimental set up is established in the laboratory. The series of

experimentation is carried out in the laboratory. In the observation, the input voltage thereby

power to air curtain is varied and its effect on discharge air velocity of air curtain is observed.

The voltage is varied in the steps of 25V with the help of dimmer stat. The speed of the

centrifugal fan of the air curtain is measured with tachometer. The discharge air velocity ismeasured with the help of turbine type anemometer in m/s. The observations and results are

presented graphically. Figure 2 shows the graph of Input voltage verses the power input to air

curtain. Figure 3 shows the graph of Input voltage verses speed of the centrifugal fan of air

curtain motor. Figure 4 shows the graph of Input voltage verses discharge air velocity of the

air curtain. From figure 2 it is clear that, as input voltage is increased, the input power also

increases. At 125V input the input power observed is 50 watts where as at input voltage 225

V it increases to 100 watts. At input of 175 V the input power recorded is 70 watts and at


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International Journal of Mech

6340(Print), ISSN 0976 6359(

input voltage of 200 V the input

air curtain is increased the pow

shows the graph of input voltage

input voltage increases the fan sthe fan speed is 822 rpm. It reac

volts fan speed stabilises even f

voltages of 200 V and 225 V t

even though there are increment

are only 28 rpm and 36 rpm. Th

velocity of 3.3 m/s and 5.2 m/s i

to 9.2 m/s at input voltage 175

for the further increment in the i

velocity stabilises beyond 175

velocity of the air curtain reveal

should run the air curtain near o

can be used, without affecting thform barrier of moving air to se

out of the air curtain device deci

the air curtain barrier. From ab

the discharge air velocity when

that equally strong air curtain c

voltage of 175 V. The further

substantial improvement in the d

Figure

nical Engineering and Technology (IJMET),

nline) Volume 4, Issue 3, May - June (2013)

81

power is 90 watts. Thus as input voltage to fa

r consumed by the motor is also found increa

verses the speed of the centrifugal fan. It is ob

eed is also increases initially. For the input volhes to 1432 rpm for the input voltage of 175 V

or increased input power to air curtain device.

e fan speed is 1460 rpm and 1468 rpm respe

s of 25 V and 50V in input voltage, the fan spe

e graph of output air velocity also shows simil

s measured at input voltage of 125V and 150

. A marginal increment of 0.4 m/s and 0.6 m

nput voltage of 25 V and 50 V respectively. T

. Figure 4 is the graph of input voltage verses

s all these details. It is clear from above discu

timum voltage to save the power else the lower

e performance of air curtain. The air curtains aarate the two environments. The velocity of t

des the quality of barrier. Higher the velocity,

ve discussion it is clear that there is not much

it is operated at 175 V, 200 V and 225 V. Th

n be obtained when the device is operated eve

increase in input of power will merely be

ischarge air velocity.

1: Photo of the Experimental set up

ISSN 0976

IAEMEmotor of the

ing. Figure 3

erved that, as

age of 125 V. Beyond 175

For the input

ctively. Thus

d increments

r nature. The

. It increases

s is observed

us output air

the output air

sion that one

power motor

e provided toe air coming

ore robust is

difference in

s we can say

n at the input

aste without


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Figure 2: Input Voltage Vs Power

Figure 3: Input Voltage Vs Fan Speed


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Figure 4: Input Voltage Vs air Velocity.

The optimum voltage there by optimum performance for this model is found to be at

175 V. During experimentation it was observed that the power required by the air curtain

device increases with increase in voltage. The power required at 175 V is 80 watts. At 200 V

and 225 V power consumed is 90 watt (12.5% more) and 100 watt (25% more) respectively.

But there is hardly any improvement observed in terms of air velocity (2% and 4%respectively). Hence it is recommended to use lower capacity motor without affecting the

performance of the air curtain device. As discussed earlier the air curtain devices are

extensively used across the globe to protect the conditioned environment. The millions of air

curtain are functioning at the malls, banks, commercial places, cold storages etc. If air

curtains devices are shifted to use lower capacity motors at optimised conditions as discussed

in the paper without affecting their performance then the huge electrical power will be saved.

Using lower power consumption motor for air curtain applications will certainly reduce the

demand of the electricity in larger extents for these commercial spaces.

CONCLUSION

The output of the air curtain device is measured in terms of velocity of air. The inputpower is varied and efforts are made to optimise the performance of the air curtain device. It

is concluded that instead of adopting the generalised approach for designing and installation

of air curtain device, it is necessary to design the air curtain device considering the particular

application. This will ensure the use of the lower capacity and lower power consumption

motor for air curtain devices for a given application. Considering the extensive use of the air

curtain devices in the entire world the demand of the electricity will be certainly reduce in the

larger extents. And thus millions of dollar will be saved in energy bills globally.

0

2

4

6

8

10

12

1 00 1 25 150 175 200 225 25 0

Maximumv

elocityinm/s

Input voltage to fan motor

Input voltage vs discharge air velocity


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REFERENCES

[1] Tassou, S. A. and Pappas T. C., Numerical Investigations into the Performance of

Doorway Vertical Air Curtains in Air-Conditioned Spaces, ASHRAE Transactions,Vol. 109, No. 1, 2003, pp. 273279.

[2] Y. T, Ge, and S A Tassou,Simulation of the performance of single jet air curtain for

vertical display cabinets, Applied Thermal Engineering, Vol. 21,2001 pp.201-219.

[3] Field B. & Loth, E., Entrainment of refrigerated air curtains down a wall,

Experimental Thermal and Fluid Science, 30, 2006, pp. 175-184,.

[4] Dr. Homayun K. Nawaz, Dr. Dana Dabiri Mazyar Amin and Ramin Faramarzi Past,

Present and future Research towards air curtain performance optimisation, OR-05-

16-4.

[5] Hampl, V., Johnston, O. E. and Murdock, D. J., Jr, Application of an Air Curtain-

Exhaust System at a Milling Process, American Industrial Hygiene Association

Journal, Vol. 49, No. 4, 1988, pp. 167175.

[6] Etkin, B. and McKinney, W. D., An Air-Curtain Fume Cabinet, AmericanIndustrial Hygiene Association Journal, Vol. 53, No. 10, 1992 pp. 625631

[7] A. Aubert and C. Solliec, Push-Pull Air Curtain Performances for VOCs

Containment in an Vol 4, No.1 2011, pp.43-50, (ISSN 1735-3645)

[8] Mr Nitin Kardekar and Dr Sane N K, Effect of humanoid shaped obstacle on the

velocity profiles of flow of air curtain International Journal of Mechanical

Engineering and Technology, Volume 3, Issue 3, 2012, pp. 511-516, ISSN Print:

0976 6340, ISSN Online: 0976 6359

[9] Kapil Chopra, Dinesh Jain, Tushar Chandana and Anil Sharma, Evaluation of

Existing Cooling Systems for Reducing Cooling Power Consumption, International

Journal of Mechanical Engineering & Technology (IJMET), Volume 3, Issue 2, 2012,

pp. 210 - 216, ISSN Print: 0976 6340, ISSN Online: 0976 6359.

Experimental Performance Analysis of Flow of Air Curtain

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