Author details

Nomenclature

Qgen heat generated inside the combustion chamber of gasifier (W)

Qloss heat loss by conduction, convection and radiation (W) Quseful the heat input to the purpose of water boiling (W)

Tcc temperature inside the combustion chamber (K) Th temperature at hot junction of ATEG (K) Rs<sup>1</sup> conductive resistance for steel-1 (K/W) Rins conductive resistance for insulation (K/W) Rs<sup>2</sup> conductive resistance for steel-2 (K/W) Rteg conductive resistance for ATEG (K/W)

Qconv heat rejected by the cold junction of ATEG (W) Th temperature at hot junction of ATEG (K) Tc temperature at cold junction of ATEG (K)

kins thermal conductivity of insulation (W/m K) Kteg thermal conductivity of TEG (W/m K)

hair convective heat transfer coefficient (W/m<sup>2</sup>K

K thermal conductance of the ATEG (W/K) R electrical conductance of the ATEG (Ω)

Qh heat absorbed by the hot junction of the ATEG (W) Qc heat rejected by the cold junction of the ATEG (W)

kp, kn thermal conductivity of p and n legs of ATEG (W/m K) ρn, ρ<sup>p</sup> electrical resistivity of p and n legs of ATEG (Ωm)

RL external resistive load of imposed on ATEG (Ω)

r5 outer diameter of ATEG (m)

α Seebeck coefficient (V/K) τ Thompson coefficient (V/K)

ZTm dimensionless figure of merit

Pout power output from the ATEG (W) n no of thermoelectric couples ɳel electrical energy efficiency (%)

Z figure of merit (1/K)

ψel exergy efficiency (%)

φ angle (radians)

I current (A)

192

L length of the combustion chamber or ATEG (m) r1 inner diameter of combustion chamber or steel-1 (m)

ks1, ks<sup>2</sup> thermal conductivities of steel-1 and steel-2 (W/m K)

r2 outer diameter of steel-1 and inner diameter of insulation (m) r3 outer diameter of insulation and inner diameter of steel-2 (m) r4 outer diameter of steel-2 and inner diameter of ATEG (m)

mfuel mass rate of fuel consumed (kg/s) CVfuel calorific value of wood (kJ/kg) Qrad radiation loss offered by the pan (W) σ Stefan-Boltzmann constant (W/m2K4)

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εpan emissivity of the pan

Apan surface area of the pan (m2) Tpan final temperature of the pan (K) Tair atmospheric air temperature (K) Qcond ¼ Q heat input to the ATEG (W)

> Sakthivadivel Duraisamy<sup>1</sup> \*, Manikandan Sundararaj<sup>3</sup> , Kumaraselvan Raja<sup>2</sup> , Ganesh Kumar Poongavanam<sup>2</sup> and Iniyan Selvarasan<sup>2</sup>

1 School of Mechanical Engineering (SMEC), Vellore Institute of Technology (VIT) University, Vellore, Tamil Nadu, India

2 Department of Mechanical Engineering, Institute for Energy Studies, College of Engineering Guindy Campus, Anna University, Chennai, India

3 SRM Institute of Science and Technology, Tamil Nadu, India

\*Address all correspondence to: sakthi2energy@gmail.com

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
