Side Of Thermoelectric Generator Research Articles

Performance of solar parabolic dish thermoelectric generator with PCM

In this work the results of experimental analysis of solar parabolic dish thermoelectric generator (TEG) are presented. The model of TEG was designed for the use of solar radiation as a heat source. The solar parabolic dish is fabricated by using polished aluminium sheet as concentrated surface. Thermoelectric generator consists of commercial thermoelectric module made of bismuth telluride (Bi2Te3) embedded between the receiver plate and Phase change material (PCM) cooled heat sink which is place on the focal plane of manual solar tracking parabolic dish collector. PCM absorbs heat during its melting thus stabilizing temperature of cold side of TEG. The concentrated solar radiation and the PCM cooled heat sink is the driving potential to generate electricity, various operating parameter like receiver plate temperature, cold side temperature, mean temperature of PCM, power output and conversion efficiency with respect to wind velocity and solar radiation are studied.

Dynamic modeling and experimental analysis of waste heat recovery from the proton exchange membrane fuel cell using thermoelectric generator

Present study demonstrates a waste heat recovery from the proton exchange membrane fuel cell (PEMFC) using thermally coupled thermoelectric generator (TEG) and metal hydride (MH) cylinder. In TEG system, cooling of cold side is very crucial that significantly affects its power output. Therefore, a strategy is proposed in which PEMFC, TEG and MH are thermally coupled for efficient waste heat recovery from the PEMFC. A mathematical model is developed for the theoretical prediction of the dynamic performance of the proposed system. The proposed strategy is compared with different cases of cold side cooling of TEG such as: 1. natural cooling 2. fan cooling. An experimental study is performed with1 kW PEMFC and 5000 L MH cylinder. An air duct is designed to extract the heat loss from the PEMFC which is utilized at the hot side of TEG while cold side is mounted on MH cylinder. Results show that PEMFC heat loss increases with increase in the operationg load, therefore TEG power output also increases. Maximum temperature difference ≈3.2 °C is achieved between hot and cold sides of TEG. It is observed that TEG modules coupled with MH can be an efficient strategy for waste heat recovery from the PEMFC.

Enhanced thermal performance of a thermoelectric generator with phase change materials

Abstract In this article, a computational study of the thermal management of thermoelectric generator (TEG) with phase change materials (PCM) is made. The test model has been developed and studied using COMSOL Multiphysics. The thermal management of thermoelectric generator is studied using the heat sink encapsulating with the phase change materials through variations in the heat input and the quantity of PCM. The results showed the considerable reduction and constant maintenance with PCM for the cold side temperature of TEG. There was enhancement in output voltage due to an increase in the temperature difference between the hot and cold sides of TEG during the phase change period. The efficiency of TEG is enhanced due to improvement in voltage of TEG. The improvements in efficiency of TEG are found to be 36.7%, 33.8%, 30% for the heat inputs of 0.1 W, 0.15 W and 0.2 W respectively when the PCM height is 3 mm. From the computational results, it is confirmed that the PCM plays vital role for the enhancement in thermal performance of TEG.

Experimental study on waste heat recovery system of an internal combustion engine using thermoelectric technology

Internal combustion engines do not effectively convert energy from the chemical reaction into useful energy, notably mechanical energy. In fact, majority of the energy are converted into heat energy, and dissipated into environment which does not fully contribute to the performance of internal combustion engine. This results in lower overall efficiency of the engine. The heat released into the environment can be converted into useful electrical energy by using thermoelectric generator (TEG). TEG consists of cold side and hot side and works based on the principle of Seebeck effect. The hot side of TEG is exposed to hot surfaces of the exhaust, and the cold side is cooled with fan cooled heat sink. The function of heat sink is to increase the temperature differences across the TEG. The conversion of waste heat into electricity by TEG in an automobile can be a good case study to replace the alternator for battery charging and increase the overall efficiency of the Internal Combustion (IC) engine. In this study, eight pieces of TEG with dimensions of 40 mm x 40 mm each were attached to a square heat exchanger. This heat exchanger was connected to the exhaust pipe of the engine. The temperature recorded in the exhaust was more than 150 °C. Thermocuples were embedded on the hot side and cold side of the thermoelectric generators to evaluate the temperature differences across the TEGs. The output of the TEGs were obtained at idle and half-throttled engine conditions. An electronic load was applied to obtain the voltage, current and the power output from the TEGs system. The TEGs were tested individually, all connected in series and parallel connections. The maximum output voltage was recorded for the series connections at 5.8 V with an average hot side temperature of 48 ° C across TEGs. Maximum power output obtained when all the TEGs connected in series was at 2.3 W.

Experimental Study of Thermoelectric Conversion Efficiency and Cold Side Thermal Management

Thermoelectric generator (TEG) while offering the advantage of operational reliability are constrained by limited efficiencies. This paper, which is from an undergraduate research project, focusses on the contribution of cold side thermal management of commercially available thermoelectric generators towards the thermal to electrical conversion efficiency for a range of hot side temperatures. Electric heating elements are used to vary the heat flux to the TEG while conventional active and passive methods employing air and water as a medium are used for dissipating heat from the cold side of TEGs. Both thermal and electrical performance parameters of the TEGs are recorded for various ambient conditions in an indoor facility corresponding to naturally occurring wind conditions. At the end, the utility and effectiveness of the cooling methods are quantified for the range of operating temperatures.

Power generation characteristics of a thermoelectric modules-based power generator assisted by fishbone-shaped fins: Part II – Effects of cooling water parameters

ABSTRACT Operation control combined with the optimization of the structure for thermoelectric generators (TEGs) based on thermoelectric modules (TEMs) is an effective method to improve the power generation characteristics of TEGs. The present study is intended to experimentally investigate the power generation characteristics including voltage and power output, and conversion efficiency of a TEM-based TEG, which is added fishbone-fins aiming to enhance heat exchange of hot inlet air to the hot side of TEG. The effects of mass flow rate (MFR) of cooling water on the power generation characteristics of TEGs are analyzed in the case of the hot inlet air temperatures of 200–500°C and a constant MFR of hot inlet air. Compared to TEM-based TEG without fishbone-shaped fins, TEM-based TEG with fishbone-shaped fins has a maximum increase by 31.37 V of voltage output and 16.49 W of power output. Conversion efficiency of TEM-based TEG with fishbone-shaped fins is determined through the temperatures of hot side and cold side as well as figure-of-merit (ZT). As a result, an average increase of 2.93% of the conversion efficiency for TEM-based TEG with fishbone-shaped fins compared to the case of TEM without fishbone-shaped fins is found. In addition, the outlet temperature of cooling water is also practically measured to evaluate the influences of fishbone-shaped fins on the heat flux transferred from hot side to cold side of TEM.

Harvesting Waste Heat Energy from Automobile Engine Exhaust Using Teg with Heat Pipes

This research investigates how the heat from car exhaust pipe line can be recovered as power using passive Thermo electric generator (TEG) using heat pipes. In this research the heat pipes are place on the cold side of TEG to remove the rising temperature and hot side of TEG is placed on the circumference of exhaust pipe line of car engine. The heat pipes with and without nano-fluids were placed on cold side of TEGs to investigate heat removal from increasing temperature and too maintain constant temperature on cold side. On the basis of results from 3D finite element simulations and experiments in the setup, the heat flow, voltage, and current were measured. The method presented in this paper gives detailed insight into how TEG modules perform in general, and also enables prediction of potential improvement in module performance by using different nano-fluids as coolants and Preliminary results were obtained. The results of Finite Element Analysis are analogous with the experimental results of TEG with water filled heat pipes with minimal possible errors. Therefore, the performance of nano-fluids in heat pipes are numerically evaluated and proposal are made for the enhancement of Module power outputs in Harnessing exhaust heat energy.

Energy management for thermoelectric generators based on maximum power point and load power tracking

Thermoelectric generators (TEGs) can be widely applied to directly convert thermal energy into electricity. Herein, we propose an energy management system for TEGs to achieve efficient energy storage and use. Specifically, we consider both the generally unstable power generation given the variable temperature difference between the hot and cold sides of TEGs and the variable load that requires the inclusion of a storage unit consisting of a battery and supercapacitor for improving the system performance. The supercapacitor mitigates energy fluctuations and reduces transients in the bus voltage, and the battery acts as a backup energy source, storing energy and delivering electricity when the load power demand is high. In addition, we propose a novel threshold control strategy based on the bus voltage intervals for the energy management system that incorporates maximum power point tracking (MPPT) and load power tracking (LPT) to maintain energy balance among the system units. MPPT aims to provide an efficient collection of thermal energy, and LPT based on fuzzy logic is used to maintain a stable bus voltage when the DC load power demand is low. The experimental results verify that the proposed LPT approach regulates the evaluated variations in DC load power with an average error of 3.5% and that the energy management properly operates under variable load power and battery state of charge.

Analysis of the use of thermoelectric generator and heat pipe for waste heat utilization

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.

Study of different heat exchange technologies influence on the performance of thermoelectric generators

A key challenge in thermoelectric power conversion is to create a significant temperature difference (ΔT) across the thermoelectric generator (TEG). And one approach to create a larger temperature difference is to enhance heat transfer of the hot side of TEG. Thus, when a thermoelectric generator has been designed and manufactured, it is found that the heat exchangers of the thermoelectric device determines its performance. This paper investigated the differences as well as the advantages and disadvantages of three typical heat exchangers in a thermoelectric setup, and the power consumed by the auxiliary equipment to improve the thermoelectric performance were taken into account. For this purpose, a mathematical model has been developed. The accuracy of this model was verified via the experiments, by constructing and testing the prototypes. The results illustrate the net power output performance of thermoelectric devices with three different type of heat exchangers. The air cooling exchangers are shown a minimum auxiliary consumption whereas the heat pipe cooling exchanger are shown to be the most effective. At last, this article gets an economic analysis, and a new evaluation index associated with the power consumption of the auxiliary equipment is proposed. The results provided some practical guidelines for the design and application of practical thermoelectric power generations.

Finite Element Analysis of Thermoelectric Generator with Aluminum Plate for Waste Heat Recovery Application

Thermoelectric generator (TEG) is the solid state device that converts the thermal gradient into electrical energy. TEG is widely used as the renewable energy source especially for the electronic equipment that operates with the small amount of electrical power. In the present analysis, the finite element analysis (FEA) using ANSYS is conducted on a model of the TEG attached with the aluminium, Al plate on the hot side of the TEG. This simple construction of TEG model was built in order to be used in the waste heat recovery application. It was shown that the changes of the width and thickness of the Al plate increased the temperature gradient between hot and cold sides of TEG. This directly increase the voltage produced by the TEG based on the Seeback effect. The increase of the thermal gradient due to the increment of thickness and width of Al plate might be because of the increase of thermal resistance of Al plate. Based on statistical analysis using full factorial of design of experiment, Al thickness play a major role in changing the performance of proposed TEG compared to that of Al width. This finding provides a valuable data in design process to build a good TEG attached with Al plate for the waste heat recovery application.

Modelling, fabrication and experimental testing of an heat sink free wearable thermoelectric generator

Thermoelectric pastes of stoichiometric Sb2Te3 and Bi2Te3 were prepared, characterized and used as active materials to fabricate a flexible heat sink free thermoelectric generator (TEG). The module was designed to be coupled to a 80mV start-up input voltage fully electrical DC-DC converter. Although practical aspects and technological limitations led to a not optimal dimensioning of the device, an improvement of its thermoelectric performance might be obtained by including an additional thick film metal layer on the two sides of TEG, as demonstrated by Finite Element Analysis (FEA) results. The designed thermopile consists of 450 thermocouples realized by blade coating of p- and n-type materials into 2mm tall vertical cavities of a pre-patterned Polydimethylsiloxane (PDMS) through-holes layer of total area 98×98mm2.For a first functional investigation, a prototype of 45 thermocouples into a footprint area of about 2.2×10−3m2 was fabricated and tested to evaluate its thermoelectric performance stand-alone and coupled with the DC-DC converter. A mean Seebeck coefficient of about 60μV/K for pn couple was calculated from experimental data, and a power of about 27nW was measured at 10K on matched load of about 6.8kΩ. A temperature difference of about 1.8°C was achieved between the junctions in working conditions next to those typical of human body wearing in indoors (quiescent air at room temperature, constant temperature of 34.8°C applied on the TEG hot side). The investigation shown that a thermopile of 450 couples requires a minimum thermal gradient of about 2°C between junctions to be able to switch on the custom voltage boost DC-DC converter.

Investigation on a mini-CPC hybrid solar thermoelectric generator unit

A hybrid solar hot water and Bi2Te3-based thermoelectric generator (TEG) unit using a heat pipe evacuated tube collector with mini-compound parabolic concentrator (mini-CPC) is proposed. In this unit, the heat from the heat pipe evacuated tube solar collector is transferred to the hot side of TEG. Simultaneously, water cooling is used at the cold side to maintain the temperature difference. Electricity is generated by TEG and the remaining heat is transferred to water at the same time. This paper investigates how to convert excess solar heat into electricity more effectively. A mathematical model regarding this unit is developed and validated. It is found that the mini-CPC can significantly improve the electrical efficiency. The optimal thermal conductance of TEG is determined, which could make the best use of excess solar heat. The excess solar heat can be effectively converted into electricity when ZT of Bi2Te3 can be improved from 100 °C to 200 °C. Using TEG with ZT = 1.0 and a geometrical concentrating ratio at 0.92, electrical and thermal efficiencies of this system are predicted to be 3.3% and 48.6% when solar radiation and water temperature are 800 Wm−2 and 20 °C, respectively.

Experimental investigation of combined heat recovery and power generation using a heat pipe assisted thermoelectric generator system

This paper explores a new method of recovering industrial waste heat and conversion to electricity using a Thermo-Electric Generator (TEG). For this purpose, a lab scale bench-top prototype of waste heat recovery and electricity conversion system was designed and fabricated. This bench top system consists of Bismuth Telluride (Bi2Te3) based TEG sandwiched between two heat pipes. The first heat pipe was connected to the hot side of the TEG and the second to the cold side of TEG. The waste heat was simulated by using a 2kW electric heater for heating the air in the system. Experiments were conducted to evaluate the system performance in terms of the heat transfer rate, heat exchanger effectiveness, and maximum output power. It was found that the highest heat exchanger effectiveness of 41% was achieved when the airspeed was set at 1.1m/s. The system could recover around 1079W of heat and produce around 7W of electric power. This equated to 0.7% of thermal-to-electric conversion efficiency. The theoretical predictions showed good agreement compared to the experimental results.

Experimental investigation of thermoelectric generator (TEG) with PCM module

In the paper, the results of experimental investigation of thermoelectric generator (TEG) are presented. The model of TEG was designed for the use of solar radiation as a heat source. An important feature of the design under study is the method of cooling of thermoelectric modules. Phase change material (PCM) absorbs heat during its melting, thus stabilizing temperature of the cool side of TEG. Basic performance characteristics, i.e. voltage and current generated vs. time, were measured during tests conducted for different electrical configurations of the unit, and for different heat fluxes on hot side of TEG. Temperature distributions in PCM container during the operation of TEG were also recorded. The reverse operation of TEG, i.e. when heat earlier accumulated in PCM is utilized, was tested as well. The results confirmed the potential of the application of phase change materials as a cooling/heating media in TEGs.

Passive Heat Recovery System Using Combination of Heat Pipe and Thermoelectric Generator

A different ways of waste heat recovery and conversion to electricity using a thermoelectric generator (TEG) assisted by heat pipes is introduced in this paper. The system consists of the TEG sandwiched between two heat pipes, one connected to the hot side of the TEG and the second one connected to the cold side of TEG. Experiments were conducted for a proof of concept of such system, and the experimental result was used to validate the theoretical model developed. It was found that both the experimental and the theoretical results share the same graphical trend in term of the rate of heat transfer and the effectiveness of heat exchanger. Further investigation in the theoretical model can narrow down the error.

Potensi Energi Listrik Pada Gas Buang Sepeda Motor

The fossil energy sources dwindling due to the many needs, especially in industrial and automotive sectors which are the largest energy users and the highest waste heat-producing. This causes many alternative energy sources are developing, included thermal energy utilization. The research utilized waste heat energy from motorcycle exhaust pipe into electrical energy with using Thermo Electric Generator (TEG). By using the thermocouple principle, difference of temperature between hot and cold side of TEG resulted voltage. Testing was conducted with three points are on head, body and mouth of the exhaust pipe. The maximum output voltage is generated in the head is greater than the other positions. At the head of exhaust, the maximum output voltage which is generated by 1 modul, 2 modules and 3 modules of TEG on each other is 1.26 V, 2.27 V and 3.43 V respectively.

Thermodynamic studies and maximum power point tracking in thermoelectric generator–thermoelectric cooler combined system

Thermoelectric generator (TEG) operated thermoelectric cooler (TEC) is a highly compatible combination for low-cooling power application. The conventional TEG–TEC combined systems have low operating efficiency and low cooling power because maximum power output from the TEG is not fully utilized. This paper proposes and analyses the combined system with maximum power point tracking technique (MPPT) to maximize the cooling power and overall efficiency. This paper also presents the effect of TEG, TEC source temperature and the effect of heat transfer area in the performance of the combined system. The thermodynamic models of the combined system are developed in MATLAB simulink environment with temperature dependent material properties and analysed for variable operating temperatures. It has been found that, in the irreversible thermodynamic model of the combined system with MPPT, when the hot and cold side of TEG and TEC are kept at a temperature difference of 150K and 10K respectively, the power output of TEG increases from 20.49W to 43.92W, cooling power of TEC increases from 32.66W to 46.51W and the overall combined system efficiency increases from 2.606% to 4.375% respectively when compared with the irreversible combined system without MPPT. The characteristics improvements obtained by this practice in the combined system for the above mentioned operating conditions is also true for other range of operating temperatures. It is also been observed that the external irreversibilities decreases the cooling power and the overall system efficiency of the combined system by 36.49% and by 16.9% respectively.

The Design, Development and Performance Evaluation of Thermoelectric Generator(TEG) Integrated Forced Draft Biomass Cookstove

The new developments in cookstove design have been made for better usage of sustainable energy and reducing the worse impact of climate change on environment. A cookstove is a combustion device which liberates lot of heat energy during cooking. In the recent developed design of TEG integrated forced draft biomasscookstove, the liberated waste heat energy is utilized for generation of electricity with the help of a thermoelectric generator. A power of 5W is achievedthrough the thermoelectric generator. The generated electricity is stored in a Li-ion battery and used further for running a 12Vd.c. fan, lighting a LED light, and charging a mobile phone. The novelty in charging a Li-ion battery is to run a fan for domestic biomass cookstovefor cleaner combustion. The fan is also used for cooling one side of TEG through heat sink for improving electrical performance of TEG and thus improving the combustion of the cookstove. This cookstove has been deployed in the rural areas to check its usability, viability, electrical and thermal performance under the umbrella of clean combustion.

Theoretical and experimental estimation of limiting input heat flux for thermoelectric power generators with passive cooling

This paper focuses on theoretical and experimental analysis used to establish the limiting heat flux for passively cooled thermoelectric generators (TEG). 2 commercially available TEG’s further referred as type A and type B with different allowable hot side temperatures (150°C and 250°C respectively) were investigated in this research. The thermal resistance of TEG was experimentally verified against the manufacturer’s specifications and used for theoretical analysis in this paper. A theoretical model is presented to determine the maximum theoretical heat flux capacity of both the TEG’s. The conventional methods are used for cooling of TEG’s and actual limiting heat flux is experimentally established for various cold end cooling configurations namely bare plate, finned block and heat pipe with finned condenser. Experiments were performed on an indoor setup and outdoor setup to validate the results from the theoretical model. The outdoor test setup consist of a fresnel lens solar concentrator with manual two axis solar tracking system for varying the heat flux, whereas the indoor setup uses electric heating elements to vary the heat flux and a low speed wind tunnel blows the ambient air past the device to simulate the outdoor breezes. It was observed that bare plate cooling can achieve a maximum heat flux of 18,125W/m2 for type A and 31,195W/m2 for type B at ambient wind speed of 5m/s while maintaining respective allowable temperature over the hot side of TEG’s. Fin geometry was optimised for the finned block cooling by using the fin length and fin gap optimisation model presented in this paper. It was observed that an optimum finned block cooling arrangement can reach a maximum heat flux of 26,067W/m2 for type A and 52,251W/m2 for type B TEG at ambient wind speed of 5m/s of ambient wind speed. The heat pipe with finned condenser used for cooling can reach 40,375W/m2 for type A TEG and 76,781W/m2 for type B TEG.