Analysis on the Performance of a Thermoelectric Generator

1999 ◽  
Vol 122 (2) ◽  
pp. 61-63 ◽  
Author(s):  
Jincan Chen ◽  
Chih Wu

An externally and internally irreversible heat engine model of thermoelectric generators is used to analyze the so-called device-design parameter introduced by O¨zkaynak et al. The simple expression of the parameter is given and its physical meaning is expounded. Moreover, the optimal range of the parameter is determined and the problems relative to the maximum power output and maximum efficiency are discussed. Some meaningful results are obtained. [S0195-0738(00)00401-5]

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Gabriel Valencia-Ortega ◽  
Sergio Levario-Medina ◽  
Marco Antonio Barranco-Jiménez

Abstract The proposal of models that account for the irreversibilities within the core engine has been the topic of interest to quantify the useful energy available during its conversion. In this work, we analyze the energetic optimization and stability (local and global) of three power plants, nuclear, combined-cycle, and simple-cycle ones, by means of the Curzon–Ahlborn heat engine model which considers a linear heat transfer law. The internal irreversibilities of the working fluid measured through the r-parameter are associated with the so-called “uncompensated Clausius heat.” In addition, the generalization of the ecological function is used to find operating conditions in three different zones, which allows to carry out a numerical analysis focused on the stability of power plants in each operation zone. We noted that not all power plants reveal stability in all the operation zones when irreversibilities are considered through the r-parameter on real-world power plants. However, an improved stability is shown in the zone limited by the maximum power output and maximum efficiency regimes.


Author(s):  
Meysam Karami Rad

Abstract Due to the relatively low efficiency of thermoelectric (TE) generators, they have mostly been used in niche applications where the unique properties of TE generators outweigh their lack of efficiency, or conditions where it is more reasonable to base the optimal design on maximum generated power rather than maximum efficiency. The aim of this work is to investigate how the different fundamental transport properties (Seebeck coefficient, thermal conductivity and electrical resistivity) in materials with equal figure of merit (ZT) impact TE module design and maximum power output. Further, we discuss and review the strategies to enhance material properties and the latest studies on the TE module performance. It is shown, that by increasing the power factor by a factor of 15 and decreasing the thermal conductivity by 13.33 in order to maintain ZT=1, power output is increased by 45%. This effect is stronger in lower module fill factor and thermal resistance of the heat source and heat sink.


2020 ◽  
Vol 45 (3) ◽  
pp. 269-290 ◽  
Author(s):  
Sergio Levario-Medina ◽  
Gabriel Valencia-Ortega ◽  
Marco Antonio Barranco-Jiménez

AbstractThe fundamental issue in the energetic performance of power plants, working both as traditional fuel engines and as combined-cycle turbines (gas-steam), lies in quantifying the internal irreversibilities which are associated with the working substance operating in cycles. The purpose of several irreversible energy converter models is to find objective thermodynamic functions that determine operation modes for real thermal engines and at the same time study the trade-off between energy losses per cycle and the useful energy. As those objective functions, we focus our attention on a generalization of the so-called ecological function in terms of an ϵ parameter that depends on the particular heat transfer law used in the irreversible heat engine model. In this work, we mathematically describe the configuration space of an irreversible Curzon–Ahlborn type model. The above allows to determine the optimal relations between the model parameters so that a power plant operates in physically accessible regions, taking into account internal irreversibilities, introduced in two different ways (additively and multiplicatively). In addition, we establish the conditions that the ϵ parameter must fulfill for the energy converter to work in an optimal region between maximum power output and maximum efficiency points.


2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Tie Liu ◽  
Zhimin Yang

To evaluate the feasibility of the performance enhancement of a thermophotovoltaic (TPV) converter by using a thermoelectric generator (TEG), a new model of a combined system is established, where the TEG is attached on the backside of the TPV converter to harvest the heat produced in the TPV converter. The effects of the voltage output of the TPV converter, band gap energy of the TPV converter, dimensionless current of the TEG, and emitter temperature on the performance of the combined system are examined numerically. It is found that the performance of the TPV converter can be enhanced by using the TEG. The percentage increment of the maximum power output density is larger than that of the maximum efficiency. There are optimally working regions of the converter voltage, dimensionless current, and band gap energy. The elevated emitter temperature results in the increase of the power output density of the combined system. However, there is an optimal emitter temperature that yields the maximum efficiency of the combined system. Moreover, the TEG is not suitable to harvest the heat produced in the TPV converter when the emitter temperature is sufficiently high.


1997 ◽  
Vol 25 (3) ◽  
pp. 197-204
Author(s):  
Mamdouh el Haj Assad

A thermodynamic analysis of a real waste-heat thermoelectric generator is investigated. The thermoelectric generator is considered as a heat engine cycle process with internal irreversibilities. The efficiency of the thermoelectric generator is expressed in terms of two non-dimensional parameters which are to be optimized. A finite-time thermodynamic analysis is used to optimize the temperatures of the hot and cold junctions of the real thermoelectric generator. A comparison between ideal and real waste-heat thermoelectric generators is demonstrated.


Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 419
Author(s):  
Congzheng Qi ◽  
Zemin Ding ◽  
Lingen Chen ◽  
Yanlin Ge ◽  
Huijun Feng

Based on finite time thermodynamics, an irreversible combined thermal Brownian heat engine model is established in this paper. The model consists of two thermal Brownian heat engines which are operating in tandem with thermal contact with three heat reservoirs. The rates of heat transfer are finite between the heat engine and the reservoir. Considering the heat leakage and the losses caused by kinetic energy change of particles, the formulas of steady current, power output and efficiency are derived. The power output and efficiency of combined heat engine are smaller than that of single heat engine operating between reservoirs with same temperatures. When the potential filed is free from external load, the effects of asymmetry of the potential, barrier height and heat leakage on the performance of the combined heat engine are analyzed. When the potential field is free from external load, the effects of basic design parameters on the performance of the combined heat engine are analyzed. The optimal power and efficiency are obtained by optimizing the barrier heights of two heat engines. The optimal working regions are obtained. There is optimal temperature ratio which maximize the overall power output or efficiency. When the potential filed is subjected to external load, effect of external load is analyzed. The steady current decreases versus external load; the power output and efficiency are monotonically increasing versus external load.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
John Mativo ◽  
Kevin Hallinan ◽  
Uduak George ◽  
Greg Reich ◽  
Robin Steininger

Abstract Typical thermoelectric generator legs are brittle which limits their application in vibratory and shear environments. Research is conducted to develop compliant thermoelectric generators (TEGs) capable of converting thermal loads to power, while also supporting shear and vibratory loads. Mathematical structural, thermal, and power conversion models are developed. Topology optimization is employed to tailor the TEG design yield maximal power production while sustaining the applied shear and vibratory loads. As a specific example, results are presented for optimized TEG legs with a void volume fraction of 0.2 that achieve compliance shear displacement of 0.0636 (from a range of 0.0504 to 0.6079). In order to achieve the necessary compliance to support the load, the power reduction is reduced by 20% relative to similarly sized void free TEG legs.


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