003 g muthu

Presenting Author

G.MuthuResearch scholar

Department of Mechanical Engineering

National Institute of Technology

Tiruchirappalli

Tamil Nadu

Co Authors

Prof. S.Shanmugam

Prof. AR.Veerappan

11 Apr 20231 National Institute of Technology Tiruchirappalli, India

Solar Parabolic Dish Thermoelectric Generator with Acrylic Cover


IntroductionMethodologyResultsDiscussionConclusionsReferences

Outline


Introduction

Concentrating solar power (CSP) systems namely parabolic trough, linear Fresnel reflector, power tower and parabolic dish can be used effectively to convert solar energy into heat.

Solar thermal thermoelectric generator is the most promising option.

Working principle - Seebeck effect.


Seebeck Effect

11 Apr 20235

National Institute of Technology Tiruchirappalli, India

Applications of Thermoelectric power

Cooling fansThermoelectric generatorsField generatorsFirewood generatorsBio-fuel generatorsVehicle exhaust waste heat generatorsWaste incineration generator systems


Structure of Thermoelectric Module


Specification of Module

Model name: TEP1-12656-0.6


Properties of Thermoelectric Module

Ref : Thermonamic Electronics (Xiamen) Co.,Ltd.,China.

Material : Bismuth Telluride alloy (Bi2 Te3)

Seebeck coefficient (α ) =190~ 200×10-6 V / K

Electrical Resistivity ()= 0.926×10-5 ~ 0.9615×10-5 Ω- m

Thermal conductivity (K) = 1.2 ~ 1.6 W/mK


Model of solar TEG


Specification of parabolic dish concentrator

Open mouth diameter of dish 3.56 mParabolic concentrator surface area 10.53 m2

Height of the parabola 0.7 mReflectivity of the concentrator 0.78Focal distance 1.11 m


Useful energy gained

The useful energy gained (Qu) on the hot side of TEG


Heat loss coefficient

If the wind flows over the receiver plate surface at Vm m/sec, the heat loss coefficient due to the wind hw, is given by (McAdams, 1954).

hw=5.7+3.8Vm


Instantaneous thermal efficiency

The instantaneous thermal efficiency of the parabolic dish collector is expressed as


Thermoelectric generator equations

The amount of heat removed from cold side (Qc) and that supplied to hot side (Qh) of the TEG are

Where S=2 N


Properties of Thermoelectric Module

92 10)9905.06.93022224()( avgTTT avgavg

102 10)6279.04.1635112()( avgTTT avgavg42 10)4131.07.27762605()( avgTTTK avgavg

Thermoelectric properties are computed from the following expression (Melcor, 2009).


Electric output & TEG Efficiency

The output (Pteg) from TEG is estimated from the relation

The efficiency of TEG


Overall efficiency

Overall system efficiency (ηoverall ) is computed from the relations


Receiver plate temperature with solar beam radiation

Results


500 600 700 800 900 1000 1100250

270

290

310

330

350

370

390

With cover

Without cover

Solar beam radiation (W/m2)

Rec

eive

r pl

ate

tem

pera

ture

(K

)

Instantaneous thermal efficiency of collector with solar beam radiation


500 600 700 800 900 1000 110062.0

63.0

64.0

65.0

66.0

67.0

68.0

With cover

Without cover


Inst

anta

neou

s th

erm

al e

ffic

ienc

y o

f pa

rabo

lic

dish

col

lect

or (

%)

The output voltage for various solar beam radiations


500 600 700 800 900 1000 11000

0.5

1

1.5

2

2.5

3

3.5

4

4.5

With cover

Without cover


Out

put

volt

age

of th

e sy

stem

(V

olts

)

Output power with solar beam radiation

11 Apr 2023

22 National Institute of Technology Tiruchirappalli, India

500 600 700 800 900 1000 11000

0.5

1

1.5

2

2.5

3

3.5

4

With cover

Without cover


Ele

ctri

cal p

ower

out

put (

w)

Overall efficiency of the System with solar beam radiation

11 Apr 2023

23 National Institute of Technology Tiruchirappalli, India

500 600 700 800 900 1000 11000

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

With cover

Without cover


Ove

rall

eff

icie

ncy

of th

e sy

stem

(%

)

Conclusions

A maximum of 383 K receiver plate temperature was obtained for TEG with cover at solar beam radiation of 1050 W/m2. It is 1.56% higher than in TEG without cover for the same solar beam radiation.

There is 2.11% improvement in overall efficiency for TEG with

cover as compared to that without cover.

The maximum voltage of the thermoelectric module achieved was 4 volts, which is 10.75% higher than TEG without cover for same solar beam radiation.

The electrical power output for modified TEG was 2.51% higher than that of the TEG without cover.


Photographic view - TEG with solar dish


References

[1] Reddy, K.S. and Sendhil Kumar, N. (2008) Combined laminar natural convection and surface radiation heat transfer in a modified cavity receiver of solar parabolic dish, International Journal of Thermal Sciences, 47, pp.1647–1657.

[2] Sukhatme, S.P. and Nayak, J.K. (2012) Solar energy: principles of thermal collection and storage, Edition 2, Tata McGraw Hill Publishing Company limited, India.

[3] Shanmugam, S., Eswaramoorthy, M., and Veerappan, AR. (2011) Mathematical Modeling of Thermoelectric Generator Driven, Applied Solar Energy, 47(1), pp31–35.


References

[4] Eswaramoorthy, M. and Shanmugam, S.(2012) Numerical Model to Compute Heat Loss in Focal Receiver of Solar Parabolic Dish Thermoelectric Generator, Energy Sources, Part A: Recovery, Utilization Environmental Effects, 34, pp 959-965.

[5] Eswaramoorthy, M. (2010) Studies on solar parabolic dish thermoelectric generator, Ph.D. Thesis, Department of Mechanical Engineering, National Institute of Technology, Tiruchirappalli, India.


Thank You