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1.
The temperature difference between the hot and cold sides of thermoelectric modules is a key factor affecting the conversion efficiency of an automotive exhaust-based thermoelectric generator (TEG). In the work discussed in this paper the compatibility of TEG cooling unit and engine cooling system was studied on the basis of the heat transfer characteristics of the TEG. A new engine-cooling system in which a TEG cooling unit was inserted was simulated at high power and high vehicle speed, and at high power and low vehicle speed, to obtain temperatures and flow rates of critical inlets and outlets. The results show that coolant temperature exceeds its boiling point at high power and low vehicle speed, so the new system cannot meet cooling requirements under these conditions. Measures for improvement to optimize the cooling system are proposed, and provide a basis for future research. 相似文献
2.
This paper describes the development and testing of a thermoelectric generator (TEG) using the exhaust heat of a 50-kW stationary
diesel power plant. The generator consists of six units that represent primary generators for each diesel engine cylinder.
Each primary generator comprises five sections with gas heat exchangers, thermoelectric modules, and liquid heat exchangers.
The sections were optimized for the exhaust gas operating temperatures. The generator electric power was 2.1 kW at rated power
of 2.2 kW, corresponding to 4.4% of the diesel plant electric power. 相似文献
3.
K. T. Wojciechowski M. Schmidt R. Zybala J. Merkisz P. Fuć P. Lijewski 《Journal of Electronic Materials》2010,39(9):2034-2038
We present herein a design for and performance measurements of a prototype thermoelectric generator (TEG) mounted on both
a spark ignition engine (0.9 dm3) and a self-ignition engine (1.3 dm3). Using the prototype TEG as a tool, benchmark studies were performed in order to compare its parameters in terms of heat
recovery from exhaust gases of both engine types. The test bed study was performed with an Automex AMX-210/100 eddy-current
brake dynamometer. To provide a comprehensive overview of the TEG operating conditions, characterization of its parameters
such as temperature distribution, heat flux density, and efficiency was done at engine speeds and loads similar to those within
the range of operation of real road conditions. 相似文献
4.
As global consumption of energy continues to increase at an exponential rate, the need to find technologies that can help
reduce this rate of consumption, particularly in passenger vehicles, is imperative. This paper provides a progress report
on the BSST-led US Department of Energy-sponsored automotive thermoelectric waste heat recovery project, which has transitioned
from phase 3 and is completing phase 4. Thermoelectric generator (TEG) development will be discussed, including modeling and
thermal cycling of subassemblies. The design includes the division of the TEG into different temperature zones, where the
subassembly materials and aspect ratios are optimized to match the temperature gradients for the particular zone. Test results
for a phase 3 quarter-scale device of the phase 4 high-temperature TEG will be discussed, where power outputs of up to 125 W
were achieved on a 600°C hot-air test bench. The design of the TEG, which uses high-power-density segmented thermoelectric
elements, has evolved from a planar design in phase 3 to a cylindrical design in phase 4. The culmination of phase 4 includes
testing of the generator on a dynamometer at the National Renewable Energy Laboratory with a high-performance production engine. 相似文献
5.
The useful waste heat potential for a bulk carrier has been evaluated as a preliminary step towards developing a thermoelectric
generator (TEG) waste heat recovery system for ships. A medium-sized bulk carrier produces 6.2 MW of waste heat, and the most
promising usable sources for the TEG are shown herein to be the exhausts from the main engine and the sludge oil incinerator. 相似文献
6.
Performance Results of a High-Power-Density Thermoelectric Generator: Beyond the Couple 总被引:1,自引:0,他引:1
D. T. Crane J. W. LAGrandeur F. Harris L. E. Bell 《Journal of Electronic Materials》2009,38(7):1375-1381
This paper describes the development of a high-power-density thermoelectric generator (TEG) with a power output of greater
than 100 W. Previous papers have described the development of the generator made of high-power-density TE couples. In this
discussion, initial thermal cycling results for the TE couples are described. The building blocks are then scaled and integrated
into a complete TEG. The design, build, and test of the TEG are discussed. The high-power-density design produces power at
greater than 250 W/L and 80 W/kg. Test results are shown for varying flow rates, temperatures, and electrical loads. 相似文献
7.
Dimitri Tatarinov M. Koppers G. Bastian D. Schramm 《Journal of Electronic Materials》2013,42(7):2274-2281
In the field of passenger transportation a reduction of the consumption of fossil fuels has to be achieved by any measures. Advanced designs of internal combustion engine have the potential to reduce CO2 emissions, but still suffer from low efficiencies in the range from 33% to 44%. Recuperation of waste heat can be achieved with thermoelectric generators (TEGs) that convert heat directly into electric energy, thus offering a less complicated setup as compared with thermodynamic cycle processes. During a specific driving cycle of a car, the heat currents and temperature levels of the exhaust gas are dynamic quantities. To optimize a thermoelectric recuperation system fully, various parameters have to be tested, for example, the electric and thermal conductivities of the TEG and consequently the heat absorbed and rejected from the system, the generated electrical power, and the system efficiency. A Simulink model consisting of a package for dynamic calculation of energy management in a vehicle, coupled with a model of the thermoelectric generator system placed on the exhaust system, determines the drive-cycle-dependent efficiency of the heat recovery system, thus calculating the efficiency gain of the vehicle. The simulation also shows the temperature drop at the heat exchanger along the direction of the exhaust flow and hence the variation of the voltage drop of consecutively arranged TEG modules. The connection between the temperature distribution and the optimal electrical circuitry of the TEG modules constituting the entire thermoelectric recuperation system can then be examined. The simulation results are compared with data obtained from laboratory experiments. We discuss error bars and the accuracy of the simulation results for practical thermoelectric systems embedded in cars. 相似文献
8.
L. A. Rosendahl Paw V. Mortensen Ali A. Enkeshafi 《Journal of Electronic Materials》2011,40(5):1111-1114
One of the most obvious early market applications for thermoelectric generators (TEG) is decentralized micro combined heat
and power (CHP) installations of 0.5 kWe to 5 kWe based on fuel cell technology. Through the use of TEG technology for waste
heat recovery it is possible to increase the electricity production in micro-CHP systems by more than 15%, corresponding to
system electrical efficiency increases of some 4 to 5 percentage points. This will make fuel cell-based micro-CHP systems
very competitive and profitable and will also open opportunities in a number of other potential business and market segments
which are not yet quantified. This paper quantifies a micro-CHP system based on a solid oxide fuel cell (SOFC) and a high-performance
TE generator. Based on a 3 kW fuel input, the hybrid SOFC implementation boosts electrical output from 945 W to 1085 W, with
1794 W available for heating purposes. 相似文献
9.
A large-scale thermoelectric generator (TEG) system has an unbalanced temperature distribution among the TEG modules, which leads to power mismatch among the modules and decreases the power output of the TEG system. To maximize the power output and minimize the power conversion loss, a centralized–distributed hybrid power conditioning architecture is presented, analyzed, and evaluated for a TEG system. The novel architecture is a combination of a conventional centralized architecture and a fully distributed architecture. By using the proposed architecture, most of the harvested power is processed by the centralized stage while only the mismatched power among the TEG modules is processed by the distributed stages. As a result, accurate and distributed maximum-power-point tracking (MPPT) for each TEG module and single-stage power conversion between the modules and load can be achieved. It offers the benefit of implementing high MPPT efficiency and high conversion efficiency simultaneously. A 50-W TEG system composed of two TEG modules is built and tested. Experimental results show that the proposed hybrid power conditioning architecture generates up to 5% more energy for a temperature difference between the two modules of only 10°C. 相似文献
10.
A thermoelectric generator (TEG) efficiency booster with buck–boost conversion and power management is proposed as a TEG battery power conditioner suitable for a wide TEG output voltage range. An inverse-coupled inductor is employed in the buck–boost converter, which is used to achieve smooth current with low ripple on both the TEG and battery sides. Furthermore, benefiting from the magnetic flux counteraction of the two windings on the coupled inductor, the core size and power losses of the filter inductor are reduced, which can achieve both high efficiency and high power density. A power management strategy is proposed for this power conditioning system, which involves maximum power point tracking (MPPT), battery voltage control, and battery current control. A control method is employed to ensure smooth switching among different working modes. A modified MPPT control algorithm with improved dynamic and steady-state characteristics is presented and applied to the TEG battery power conditioning system to maximize energy harvesting. A 500-W prototype has been built, and experimental tests carried out on it. The power efficiency of the prototype at full load is higher than 96%, and peak efficiency of 99% is attained. 相似文献
11.
Thermoelectric recovery of automobile waste exhaust heat has been identified as having potential for reducing fuel consumption
and environmentally unfriendly emissions. Around 35% of combustion energy is discharged as heat through the exhaust system,
at temperatures which depend upon the engine’s operation and range from 800°C to 900°C at the outlet port to less than 50°C
at the tail-pipe. Beneficial reduction in fuel consumption of 5% to 10% is widely quoted in the literature. However, comparison
between claims is difficult due to nonuniformity of driving conditions. In this paper the available waste exhaust heat energy
produced by a 1.5 L family car when undergoing the new European drive cycle was measured and the potential thermoelectric
output estimated. The work required to power the vehicle through the drive cycle was also determined and used to evaluate
key parameters. This enabled an estimate to be made of the engine efficiency and additional work required by the engine to
meet the load of a thermoelectric generating system. It is concluded that incorporating a thermoelectric generator would attract
a penalty of around 12 W/kg. Employing thermoelectric modules fabricated from low-density material such as magnesium silicide
would considerably reduce the generator weight penalty. 相似文献
12.
Sumeet Kumar Stephen D. Heister Xianfan Xu James R. Salvador Gregory P. Meisner 《Journal of Electronic Materials》2013,42(4):665-674
A numerical model has been developed to simulate coupled thermal and electrical energy transfer processes in a thermoelectric generator (TEG) designed for automotive waste heat recovery systems. This model is capable of computing the overall heat transferred, the electrical power output, and the associated pressure drop for given inlet conditions of the exhaust gas and the available TEG volume. Multiple-filled skutterudites and conventional bismuth telluride are considered for thermoelectric modules (TEMs) for conversion of waste heat from exhaust into usable electrical power. Heat transfer between the hot exhaust gas and the hot side of the TEMs is enhanced with the use of a plate-fin heat exchanger integrated within the TEG and using liquid coolant on the cold side. The TEG is discretized along the exhaust flow direction using a finite-volume method. Each control volume is modeled as a thermal resistance network which consists of integrated submodels including a heat exchanger and a thermoelectric device. The pressure drop along the TEG is calculated using standard pressure loss correlations and viscous drag models. The model is validated to preserve global energy balances and is applied to analyze a prototype TEG with data provided by General Motors. Detailed results are provided for local and global heat transfer and electric power generation. In the companion paper, the model is then applied to consider various TEG topologies using skutterudite and bismuth telluride TEMs. 相似文献
13.
K. Salzgeber P. Prenninger A. Grytsiv P. Rogl E. Bauer 《Journal of Electronic Materials》2010,39(9):2074-2078
The power output of a thermoelectric generator (TEG) was investigated under engine partial-load operation based on measured
exhaust gas temperatures and mass flow rates. Materials with properties required for highend temperature TE couples (>500°C)
were evaluated. Various possible material combinations for p- and n-legs of these couples as well as the conflicting targets of high efficiency and low cost as required for automotive mass
production are discussed. New skutterudite materials for both p- and n-legs as identified during a joint research project are presented, which can help to overcome this conflict. Efficiencies
>10% were achieved with these new materials, which have potentially twofold lower production costs than telluride-based materials
due to the price of their elements. Some potential for improvement in efficiency and costs has been identified by developing
highly integrated TEG units, specifically designed for automotive applications. These initial results of the material development
and the evaluation of different integration concepts will be applied in a subsequent step for the fabrication of a pilot number
of TEG modules/units. 相似文献
14.
Kai Sun Longxian Ni Min Chen Hongfei Wu Yan Xing Lasse Rosendahl 《Journal of Electronic Materials》2013,42(7):2157-2164
To develop practical thermoelectric generator (TEG) systems, especially radioisotope thermoelectric power supplies for deep-space exploration, a power conditioning stage with high step-up gain is indispensable. This stage is used to step up the low output voltage of thermoelectric generators to the required high level. Furthermore, maximum power point tracking control for TEG modules needs to be implemented into the power electronics stages. In this paper, the temperature-dependent electrical characteristics of a thermoelectric generator are analyzed in depth. Three typical high step-up power converters suitable for TEG applications are discussed: an interleaved boost converter, a boost converter with a coupled inductor, and an interleaved boost converter with an auxiliary transformer. A general comparison of the three high step-up converters is conducted to study the step-up gain, conversion efficiency, and input current ripples. The interleaved boost converter with an auxiliary transformer is found to be the most suitable topology for TEG applications, which is verified by experiments. 相似文献
15.
L. I. Anatychuk V. Ya. Mykhailovsky L. T. Strutynska 《Journal of Electronic Materials》2010,39(9):1404-1407
The use of thermoelectric generators (TEGs) in heating systems enables autonomous supply of power to automatic safety devices,
creation of optimized gas mixtures, and automation and precise temperature control of exhaust gas and heat carriers. It is
particularly important to make heating systems independent of the district electric grid. Results of research and development
efforts on a TEG for supplying power to electric devices of self-contained heating and boiler systems are presented. A TEG
physical model is proposed, and results of computer simulation and optimization of its basic power and design parameters are
given. Two TEG design variants (single and double sided) are considered. Their advantages and shortcomings are discussed.
On the basis of theoretical calculations, a prototype TEG for a 10.5-kW boiler is built. At water heating system temperatures
from 35°C to 80°C, the TEG electric power is 50 W to 65 W, which is used to supply a circulation pump for forced liquid heat
carrier delivery (30 W to 40 W) and a fan for removal of fuel combustion products from the boiler’s smoke chamber (5 W to
7 W). 相似文献
16.
This paper looks at thermoelectric power generation from waste heat from a biomass drier. In this study, the researchers selected
four thermoelectric modules: two thermoelectric cooling modules (Model A: MT2-1,6-127 and Model B: TEC1-12708) and two thermoelectric
power generation modules (Model C: TEP1-1264-3.4 and Model D: TEG1-1260-5.1) for testing at temperatures between 25°C and
230°C. Test results indicated that the thermoelectric TEC1-12708 could generate a maximum power output of 1 W/module and TEP1-1264-3.4,
TEG1-1260-5.1, and MT2-1,6-127 could generate 1.07 W/module, 0.88 W/module, and 0.76 W/module, respectively. Therefore, the
thermoelectric cooling of TEC1-12708 was appropriate to use for thermoelectric power generation from waste heat. The experiments
used four ventilation fans (6 W, 2.50 m3/s) and 12 thermoelectric modules which were installed in the back of a charcoal brazier. The experiments were conducted and
tested in conditions of recycling 100%, 75%, 50%, and 25% of outlet air. Testing results identified that the temperatures
of the drying room were 81°C, 76°C, 70°C, and 64°C, respectively. The power generation system could generate about 22.4 W
(14 V, 1.6 A) with an air flow of 9.62 m3/s. The thermoelectric module can convert 4.08% of the heat energy to electrical energy. 相似文献
17.
The placement of thermoelectric generators (TEGs) in vehicles is analyzed, taking into account the interaction of the TEG
with the internal combustion engine (ICE). Alternative locations of the TEG directly in the ICE, on the exhaust pipe, and
on the cooling system are considered. In all three cases there is a conflict between the two thermal machines, which reduces
the total efficiency of the thermodynamic (ICE + TEG) system. It is shown that the cause of the conflict is the low efficiency
of the TEG (η
TEG < 0.05) compared with that of the ICE (η
TEG < 0.4); this conflict increases with the net power W
e and decreases with increasing η
TEG. For this reason, attainable values of W
e, as well as waste heat recovery in cars by the TEG, are significantly limited. Also, some problems of finding materials for
automotive TEGs and ways to suppress the parasitic Thomson effect in TEG legs are discussed. 相似文献
18.
Amir Yadollah Faraji Randeep Singh Masataka Mochizuki Aliakbar Akbarzadeh 《Journal of Electronic Materials》2014,43(6):1940-1945
All liquid heating systems, including solar thermal collectors and fossil-fueled heaters, are designed to convert low-temperature liquid to high-temperature liquid. In the presence of low- and high-temperature fluids, temperature differences can be created across thermoelectric devices to produce electricity so that the heat dissipated from the hot side of a thermoelectric device will be absorbed by the cold liquid and this preheated liquid enters the heating cycle and increases the efficiency of the heater. Consequently, because of the avoidance of waste heat on the thermoelectric hot side, the efficiency of heat-to-electricity conversion with this configuration is better than that of conventional thermoelectric power generation systems. This research aims to design and analyze a thermoelectric power generation system based on the concept described above and using a low-grade heat source. This system may be used to generate electricity either in direct conjunction with any renewable energy source which produces hot water (solar thermal collectors) or using waste hot water from industry. The concept of this system is designated “ELEGANT,” an acronym from “Efficient Liquid-based Electricity Generation Apparatus iNside Thermoelectrics.” The first design of ELEGANT comprised three rectangular aluminum channels, used to conduct warm and cold fluids over the surfaces of several commercially available thermoelectric generator (TEG) modules sandwiched between the channels. In this study, an ELEGANT with 24 TEG modules, referred to as ELEGANT-24, has been designed. Twenty-four modules was the best match to the specific geometry of the proposed ELEGANT. The thermoelectric modules in ELEGANT-24 were electrically connected in series, and the maximum output power was modeled. A numerical model has been developed, which provides steady-state forecasts of the electrical output of ELEGANT-24 for different inlet fluid temperatures. 相似文献
19.
Hiroshi Nagayoshi Hiroshi Maiwa Takenobu Kajikawa 《Journal of Electronic Materials》2013,42(7):2282-2286
A thermoelectric (TE) power conditioner maintaining high efficiency over a wide input power range has been developed. Variable switching frequency operation is shown to give an improvement in efficient operating range. The input range showing more than 90% conversion efficiency is expanded to more than 25% by introducing a low-power controller circuit and variable switching frequency control. The TE power conditioner showed excellent response against a change in thermoelectric generator (TEG) output and load, making it suitable for automotive applications. 相似文献
20.
Takeshi Terayama Susumu Nagata Yohei Tanaka Akihiko Momma Tohru Kato Masaru Kunii Atsushi Yamamoto 《Journal of Electronic Materials》2013,42(7):2306-2313
Solid oxide fuel cells (SOFCs) are being researched around the world. In Japan, a compact SOFC system with rated alternative current (AC) power of 700 W has become available on the market, since the base load electricity demand for a standard home is said to be less than 700 W AC. To improve the generating efficiency of SOFC systems in the 700-W class, we focused on thermoelectric generation (TEG) technology, since there are a lot of temperature gradients in the system. Analysis based on simulations indicated the possibility of introducing thermoelectric generation at the air preheater, steam generator, and exhaust outlet. Among these options, incorporating a TEG heat exchanger comprising multiple CoSb3/SiGe-based TEG modules into the air preheater had potential to produce additional output of 37.5 W and an improvement in generating efficiency from 46% to 48.5%. Furthermore, by introducing thermoelectric generation at the other two locations, an increase in maximum output of more than 50 W and generating efficiency of 50% can be anticipated. 相似文献