scholarly journals Thermoelectric Generator with Passive Biphasic Thermosyphon Heat Exchanger for Waste Heat Recovery: Design and Experimentation

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5815
Author(s):  
Miguel Araiz ◽  
Álvaro Casi ◽  
Leyre Catalán ◽  
Patricia Aranguren ◽  
David Astrain

One of the measures to fight against the current energy situation and reduce the energy consumption at an industrial process is to recover waste heat and transform it into electric power. Thermoelectric generators can be used for that purpose but there is a lack of experimental studies that can bring this technology closer to reality. This work presents the design, optimizations and development of two devices that are experimented and compared under the same working conditions. The hot side heat exchanger of both generators has been designed using a computational fluid dynamics software and for the cold side of the generators two technologies have been analysed: a finned dissipater that uses a fan and free convection biphasic thermosyphon. The results obtained show a maximum net generation of 6.9W in the thermoelectric generator with the finned dissipater; and 10.6W of power output in the generator with the biphasic thermosyphon. These results remark the importance of a proper design of the heat exchangers, trying to get low thermal resistances at both sides of the thermoelectric modules, as well as, the necessity of considering the auxiliary consumption of the equipment employed.

2014 ◽  
Vol 979 ◽  
pp. 421-425 ◽  
Author(s):  
Narong Sangwaranatee

This research studies the alternative way of electricity generating from the waste heat of economy oven by using 4 modules of thermoelectric modules. The hot side of thermoelectric module is attached to the heat plate while the cold side is installed on the rectangular, plate-fin heat exchanger. Variety of system adjustments were used during this study in terms of finding the maximum electric power rate. Adjusting the heating value and the electrical resistance to the thermoelectric was the procedure in this study. From the research, we found out that at the temperature of 200°C on the heat pad, the released maximum electric current was 4.5 W. The percentage of heat converting to electric current was 11.9%, with the 0.84 A and 5.35 V. The efficiency of the economy oven was 23.20%, and comes up to 23.39% while generating power via thermoelectric module.


Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3276 ◽  
Author(s):  
Jan Wajs ◽  
Michał Bajor ◽  
Dariusz Mikielewicz

In this paper a patented design of a heat exchanger with minijets, with a cylindrical construction is presented. It is followed by the results of its systematic experimental investigations in the single-phase convection heat transfer mode. Based on these results, validation of selected correlations (coming from the literature) describing the Nusselt number was carried out. An assessment of the heat exchange intensification level in the described heat exchanger was done through the comparison with a shell-and-tube exchanger of a classical design. The thermal-hydraulic characteristics of both units were the subjects of comparison. They were constructed for the identical thermal conditions, i.e., volumetric flow rates of the working media and the media temperatures at the inlets to the heat exchanger. The experimental studies of both heat exchangers were conducted on the same test facility. An increase in the heat transfer coefficients values for the minijets heat exchanger was observed in comparison with the reference one, whereas the generated minijets caused greater hydraulic resistance. Experimentally confirmed intensification of heat transfer on the air side, makes the proposed minijets heat exchanger application more attractive, for the waste heat utilization systems from gas sources.


Author(s):  
Anitha Angeline A ◽  
Jayakumar J

The performance of (Bi<sub>2</sub>Te<sub>3</sub>-PbTe) hybrid thermoelectric generator (TEG)<strong> </strong>composed of n-type Bismuth Telluride and p-type Lead Telluride semiconductor materials is presented in this paper. <strong> </strong>The effect of different performance parameters such as output voltage, output current, output power, maximum power output, open circuit voltage, Seebeck co-efficient, electrical resistance, thermal conductance, figure of merit, efficiency, heat absorbed and heat removed based on maximum conversion and power efficiency have been theoretically analyzed by varying the hot side temperature of the hybrid thermoelectric generator up to 350<sup>o</sup>C and by varying the cold side temperature from 30<sup>o</sup>C to 150<sup>o</sup>C. The results showed that a maximum power output of 21.7 W has been obtained with the use of one hybrid thermoelectric module for a temperature difference of 320<sup>o</sup>C between the hot and cold side of the thermoelectric generator at matched load resistance. The figure of merit was found to be around 1.28 which makes its usage possible in the intermediate temperature (250<sup>o</sup>C to 350<sup>o</sup>C) applications such as heating of Biomass waste, heat from Biomass cook stoves or waste heat recovery etc. It is also observed that the hybrid thermoelectric generator offers superior performance over 250<sup>o</sup>C of the hot side temperature, compared to standard Bi<sub>2</sub>Te<sub>3 </sub>modules.


Author(s):  
Uzziel Caldiño-Herrera ◽  
Delfino Cornejo-Monroy ◽  
Shehret Tilvaldyev ◽  
José Omar Dávalos-Ramírez

In this paper we present the implementation of a system based on organic Rankine cycle coupled to a heat discharge of an industrial process. Waste heat is used as an energy source input to the system, which uses this energy to evaporate an organic fluid and expand it in a turbine, where mechanical power is produced. The system consists of 4 processes and the heat exchanger is specially analyzed. According to the availability of heat energy, the heat exchanger was designed to achieve the maximum efficiency in the energy system. Likewise, the maximum thermal efficiency of the ORC system is calculated as a function of the available energy, the energy source temperature and the available mass flow rate. By these calculations, the working fluid and the suitable operating conditions were selected through a thermodynamic analysis.


Author(s):  
Dongxu Ji ◽  
Alessandro Romagnoli

In order to design an effective thermoelectric generator (TEG) heat exchanger for waste heat recovery, an accurate model is required for system design and performance predicting. In this paper, 1-D model is developed in MATLAB, taking into consideration of the multi-physics phenomena within TEG. The proposed model is different from existing thermoelectric models which mainly focus on the thermoelectric couple or device level without providing any guidance for designing an optimal system. When optimizing some TEG parameters, the optimal value found in a device level model might not be suitable when put into a waste heat recovery system. Therefore, in order to develop an optimized TEG system with optimum output power performance, a more comprehensive thermoelectric model integrated with the other components is needed. The current model integrates the thermoelectric module with the heat exchangers. Through this study, we found that the heat exchanger and module design have an impact on the total TEG output power in waste heat recovery system and a systematic design approach is needed.


2018 ◽  
Vol 67 ◽  
pp. 02057
Author(s):  
Imansyah Ibnu Hakim ◽  
Nandy Putra ◽  
Mohammad Usman

Waste heat recovery is one way to reduce the use of fossil fuels, one of them is by using thermoelectric generator to convert waste heat into Thermoelectric Generator (TEGs) is a module that can convert heat into electrical power directly, using Seebeck effect and Peltier effect as its working principle, so it can increase efficiency of energy consumption by utilizing waste heat from an instrument that generate waste heat. The focus of this research is to find the output voltage of TEG by utilizing the temperature difference on the cold side and the heat side of the TEGs. The heat side of the module will be given heat from the heater as a simulation of the heat from hot water, and on the cold side heat pipes will be used to remove the heat on the cold side of TEGs. The result, output voltage that generated by using 4 module TEGs that arranged to Thermal Series - Series Circuit and using 2 heat pipes is 2.1-volt, and then it is possible to use for phone charger.


2013 ◽  
Vol 743-744 ◽  
pp. 105-110
Author(s):  
Hong Tao Yu ◽  
Zhi Feng Zhang ◽  
Qing Quan Qiu ◽  
Qiang Sun ◽  
Guo Min Zhang ◽  
...  

Semiconductor thermoelectric generators have a series of advantages, such as compact volume, high-level reliability, and effective power generation in the presence of temperature difference. In many occasions, as a result of high voltage, electrical equipments can't be measured by the way of direct contact. In order to avoid equipment faults caused by low-voltage contact, a thermoelectric generator which uses waste heat of electrical equipments in service was designed. Electrical equipments often operate below 400K, and in this condition Bi2Te3 shows an outstanding performance of power generation. In order to solve the problems of little temperature difference and output power on steady-state, two methods were introduced. On the one hand, the temperature difference can be increased by filling with thermal insulation padding between the p-n junctions and using a heat sink in the cold side, and on the other hand, the output voltage and power will be augmented by increasing the number of p-n junctions. These methods have been proved effectively by simulation and experiment with promising outcomes.


Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3137
Author(s):  
Rui Quan ◽  
Tao Li ◽  
Yousheng Yue ◽  
Yufang Chang ◽  
Baohua Tan

To study on the thermoelectric power generation for industrial waste heat recovery applied in a hot-air blower, an experimental thermoelectric generator (TEG) bench with the hexagonal heat exchanger and commercially available Bi2Te3 thermoelectric modules (TEMs) was established, and its performance was analyzed. The influences of several important influencing factors such as heat exchanger material, inlet gas temperature, backpressure, coolant temperature, clamping pressure and external load current on the output power and voltage of the TEG were comparatively tested. Experimental results show that the heat exchanger material, inlet gas temperature, clamping pressure and hot gas backpressure significantly affect the temperature distribution of the hexagonal heat exchanger, the brass hexagonal heat exchanger with lower backpressure and coolant temperature using ice water mixture enhance the temperature difference of TEMs and the overall output performance of TEG. Furthermore, compared with the flat-plate heat exchanger, the designed hexagonal heat exchanger has obvious advantages in temperature uniformity and low backpressure. When the maximum inlet gas temperature is 360 °C, the maximum hot side temperature of TEMs is 269.2 °C, the maximum clamping pressure of TEMs is 360 kg/m2, the generated maximum output power of TEG is approximately 11.5 W and the corresponding system efficiency is close to 1.0%. The meaningful results provide a good guide for the system optimization of low backpressure and temperature-uniform TEG, and especially demonstrate the promising potential of using brass hexagonal heat exchanger in the automotive exhaust heat recovery without degrading the original performance of internal combustion engine.


2018 ◽  
Vol 238 ◽  
pp. 02001
Author(s):  
Yihuai Li ◽  
Zihua Wu ◽  
Huaqing Xie ◽  
Dingcong Tang ◽  
Yuanyuan Wang ◽  
...  

Enhancement of the heat transfer of the cold side is one of the approaches to improve the performance of thermoelectric generator systems (TEGs). In order to investigate viability and further performance of the TEG for waste heat recovery in industry area, a small low-temperature waste heat thermoelectric generator setup has been constructed with graphene oxide (GO) nanofluids as coolants in the paper. The results showed excellent stability of GO nanofluids through the preparation of two-step method to be applied in the TEGs .The highest open output voltage of TEG system were obtained by 0.15% weight fraction of GO nanofluids as coolant when the temperature difference (△T) was designed at 95K and the hot side temperature was fixed at 373K in the TEGs. Compared with conventional glycol-water base fluid as coolant, the highest open voltage enhancement ratio has reached 65.26% in the TEGs.


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