Waste heat recovery through plate heat exchanger based thermoelectric generator system

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.

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Experimental Study on a Thermoelectric Generator for Industrial Waste Heat Recovery Based on a Hexagonal Heat Exchanger

Energies ◽

10.3390/en13123137 ◽

2020 ◽

Vol 13 (12) ◽

pp. 3137

Author(s):

Rui Quan ◽

Tao Li ◽

Yousheng Yue ◽

Yufang Chang ◽

Baohua Tan

Keyword(s):

Heat Exchanger ◽

Industrial Waste ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Thermoelectric Generator ◽

Waste Heat ◽

Coolant Temperature ◽

Gas Temperature ◽

Industrial Waste Heat ◽

Clamping Pressure

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.

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Artificial Neural Network and Adaptive Neuro-Fuzzy Interface System Modelling to Predict Thermal Performances of Thermoelectric Generator for Waste Heat Recovery

Symmetry ◽

10.3390/sym12020259 ◽

2020 ◽

Vol 12 (2) ◽

pp. 259 ◽

Cited By ~ 5

Author(s):

Kunal Sandip Garud ◽

Jae-Hyeong Seo ◽

Chong-Pyo Cho ◽

Moo-Yeon Lee

Keyword(s):

Thermal Efficiency ◽

Prediction Accuracy ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Thermoelectric Generator ◽

Waste Heat ◽

Anfis Model ◽

Generator System ◽

Neuro Fuzzy ◽

Optimum Model

The present study elaborates the suitability of the artificial neural network (ANN) and adaptive neuro-fuzzy interface system (ANFIS) to predict the thermal performances of the thermoelectric generator system for waste heat recovery. Six ANN models and seven ANFIS models are formulated by considering hot gas temperatures and voltage load conditions as the inputs to predict current, power, and thermal efficiency of the thermoelectric generator system for waste heat recovery. The ANN model with the back-propagation algorithm, the Levenberg–Marquardt variant, Tan-Sigmoidal transfer function and 25 number of hidden neurons is found to be an optimum model to accurately predict current, power and thermal efficiency. For current, power and thermal efficiency, the ANFIS model with pi-5 or gauss-5-membership function is recommended as the optimum model when the prediction accuracy is important while the ANFIS model with gbell-3-membership function is suggested as the optimum model when the prediction cost plays a crucial role along with the prediction accuracy. The proposed optimal ANN and ANFIS models present higher prediction accuracy than the coupled numerical approach.

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Experimental investigation on thermoelectric generator with non-uniform hot-side heat exchanger for waste heat recovery

Energy Conversion and Management ◽

10.1016/j.enconman.2017.08.030 ◽

2017 ◽

Vol 150 ◽

pp. 403-414 ◽

Cited By ~ 31

Author(s):

Xing Lu ◽

Xingfei Yu ◽

Zuoming Qu ◽

Qiuwang Wang ◽

Ting Ma

Keyword(s):

Experimental Investigation ◽

Heat Exchanger ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Thermoelectric Generator ◽

Waste Heat

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Multiobjective Optimization of a Plate Heat Exchanger in a Waste Heat Recovery Organic Rankine Cycle System for Natural Gas Engines

Entropy ◽

10.3390/e21070655 ◽

2019 ◽

Vol 21 (7) ◽

pp. 655 ◽

Cited By ~ 21

Author(s):

Guillermo Valencia ◽

José Núñez ◽

Jorge Duarte

Keyword(s):

Heat Transfer ◽

Thermal Efficiency ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Waste Heat ◽

Organic Rankine Cycle ◽

Rankine Cycle ◽

Plate Heat Exchanger ◽

Exhaust Gas ◽

Plate Heat

A multiobjective optimization of an organic Rankine cycle (ORC) evaporator, operating with toluene as the working fluid, is presented in this paper for waste heat recovery (WHR) from the exhaust gases of a 2 MW Jenbacher JMS 612 GS-N.L. gas internal combustion engine. Indirect evaporation between the exhaust gas and the organic fluid in the parallel plate heat exchanger (ITC2) implied irreversible heat transfer and high investment costs, which were considered as objective functions to be minimized. Energy and exergy balances were applied to the system components, in addition to the phenomenological equations in the ITC2, to calculate global energy indicators, such as the thermal efficiency of the configuration, the heat recovery efficiency, the overall energy conversion efficiency, the absolute increase of engine thermal efficiency, and the reduction of the break-specific fuel consumption of the system, of the system integrated with the gas engine. The results allowed calculation of the plate spacing, plate height, plate width, and chevron angle that minimized the investment cost and entropy generation of the equipment, reaching 22.04 m2 in the heat transfer area, 693.87 kW in the energy transfer by heat recovery from the exhaust gas, and 41.6% in the overall thermal efficiency of the ORC as a bottoming cycle for the engine. This type of result contributes to the inclusion of this technology in the industrial sector as a consequence of the improvement in thermal efficiency and economic viability.

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