Optimization Design of an Intermediate Fluid Thermoelectric Generator for Exhaust Waste Heat Recovery

Abstract

The intermediate fluid thermoelectric generator (IFTEG) represents a novel approach to power generation, predicated upon the principles of gravity heat pipe technology. Its key advantages include high-power output and a compact module area. The generator’s performance, however, is influenced by the variable exhaust parameters typical of automobile operation, which presents a significant challenge in the design process. The present study establishes a mathematical model to optimize the design of the IFTEG. Our findings suggest that the optimal module area sees substantial growth with an increase in both the exhaust heat exchanger area and the exhaust flow rate. Interestingly, the optimal module area appears to demonstrate a low sensitivity to changes in exhaust temperature. To address the challenge of determining the optimal module area, this study introduces the concept of peak power deviation. This method posits that any deviation from the optimal module area results in an equivalent power deviation. For instance, with an exhaust heat exchanger area of 1.6 m2, the minimum peak power deviation is 27.5%, corresponding to a design module area of 0.124 m2. As such, the actual output power’s deviation from the maximum achievable output power will not exceed 27.5% for any given set of exhaust parameters. This study extends its findings to delineate the relationship between the optimal design module area and the exhaust heat exchanger area. These insights could serve as a useful guide for the design of future power generators.

A Review of Thermoelectric Generators in Automobile Waste Heat Recovery Systems for Improving Energy Utilization

“…A superiority based on the power and efficiency of the IFTEG compared to the conventional TEG is highlighted in Figure 18. Zhang et al [152] adopted a peak power deviation approach for optimizing the thermoelectric module area of an IFTEG system, where water was used as an intermediate fluid. The optimal module area for the maximum power output is a function of the exhaust's heat exchanger area, temperature, and flow rate.…”

“…They are often called superconductors, as they can transfer large quantities of thermal energy with almost zero heat loss. In heat pipes, heat is transferred by boiling and subsequently condensing fluid in the confined space of the Zhang et al [152] adopted a peak power deviation approach for optimizing the thermoelectric module area of an IFTEG system, where water was used as an intermediate fluid. The optimal module area for the maximum power output is a function of the exhaust's heat exchanger area, temperature, and flow rate.…”

Optimal Design and Multi-Parameter Sensitivity Analysis of a Segmented Thermoelectric Generator

“…Thermoelectric generators (TEGs), as solid green energy conversion devices, have been extensively studied in recent years due to their advantages of high reliability and compactness, and their lack of pollution and moving parts [1]. TEGs have been applied in solar energy utilization [2], waste heat recovery [3], wearable electronics [4], etc. However, the low conversion efficiency of TEGs is one of the main obstacles to their wide application.…”