Analysis of the Performance of a Solar Thermoelectric Generator for Variable Leg Geometry with Nanofluid Cooling

Cristian Francisco Ramos-Castañeda,Miguel Angel Olivares-Robles,Juan Vicente Méndez-Méndez

doi:10.3390/pr9081352

Cristian Francisco Ramos-Castañeda, Miguel Angel Olivares-Robles + Show 1 more

Open Access

https://doi.org/10.3390/pr9081352

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Journal: Processes	Publication Date: Aug 1, 2021
Citations: 13	License type: CC BY 4.0

Affiliation: Instituto Politécnico Nacional

Abstract

In this study, the impact of nanofluid use in solar-thermoelectric generators (Solar-TEG) on thermal performance is investigated through analysis and simulation methodology. For conventional cooling analysis, we use air as a coolant and graphene nanoplatelet aqueous nanofluids (GNAN) for nanofluid cooling. We make a comparison between traditional and nanofluid cooling to find the best performance. GNAN at a dispersion of 0.025, 0.05, 0.075, and 0.1-wt% are added to the cooling system. GNAN has been used in the technological development of energy conversion. It has been proposed as a material to achieve better efficiency in Solar-TEG. Five different geometries are developed to analyze the efficiency in a Solar-TEG to find the optimal design. The impact of the thermal concentration relationship, substrate area, and convective transfer coefficient on Solar-TEG performance is investigated. To simplify and speed up simulations, we use equivalent models based on FEM. We are considering the properties of temperature-dependent semiconductors. For thermoelement materials, we use lead-tellurium. Lead-tellurium is an excellent material for thermoelectric study and supports large temperature ranges (up to 750 K). The thermal concentration relationship depends on the substrate area, which affects the efficiency of Solar-TEG. The maximum efficiency between the five geometry types is 5.53%, with a substrate of 110 × 100 mm2. The efficiency and output power using 0.1% wt GNAN as the refrigerant is enhanced by 14.74% and 26.39%. GNAN cooling improves compared to conventional fluid cooling in a Solar-TEG. Different convection coefficients are used to verify this fact.

Highlights

Thermoelectric generation systems (TEG) have undergone important advances in recent years due to the development of semiconductor materials, and thermoelectric devices have even been incorporated into domestic accessories
If a temperature gradient is applied in a TEG system, there will be an electric field in the opposite direction associated with the thermoelectric system
The results show that the heat, efficiency, output power, and voltage absorbed by the hot surfaces of the TEG system were increased by the liquid nano coolant

Summary

Introduction

Thermoelectric generation systems (TEG) have undergone important advances in recent years due to the development of semiconductor materials, and thermoelectric devices have even been incorporated into domestic accessories. A thermoelectric generator (TEG) is usually composed of two thermoelements connected in series, an n-type and a p-type. Thermoelements are connected by a metal (copper) and sealed by an aluminum ceramic material on the upper and lower surfaces [3]. If a temperature gradient is applied in a TEG system, there will be an electric field in the opposite direction associated with the thermoelectric system. This phenomenon is called the thermoelectric effect [7,8]

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Discussion

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