Semiconductor Thermoelectric Generator Research Articles

Enhancing the performance of PVT-TEG power generation systems by heat pipes and Fe3O4 nanofluids

In recent years, enhancing the cooling of photovoltaic (PV) panels to improve overall energy efficiency has become a significant focus. In this study, we propose an improved power generation system integrating semiconductor thermoelectric generators (TEGs). The integration involves the installation of several heat pipes and serpentine copper tubes on the back of PV panels, with nanofluids flowing through the copper tubes as the working fluid, effectively cooling the PV panels. The copper tube is connected to the heat exchanger on the high-temperature side of the TEGs, forming a closed-loop circulation system. Consequently, the cooling fluid transfers heat to the hot surface of the TEGs, utilizing waste heat generated by the PV panels for electricity generation. The TEGs consist of 10 thermoelectric modules, with the low-temperature end in contact with the finned aluminum plate (TEGs radiator) and actively cooled by natural air cooling. Additionally, to validate the design rationale, multiple sets of comparative experiments were arranged. The experiments utilized nanofluids with volume fractions of 0.5 %, 1 %, 2 %, and 3 %, and water, as the cooling fluid. The experimental results demonstrated that the maximum operating temperature of the reference PV panel can reach 81.9 °C, and the average and maximum exergy efficiencies throughout a day are recorded at 16.91 % and 31.84 %, respectively. It’s noteworthy that the most significant cooling effect occurs when the nanofluid volume fraction is 2 %, reducing the maximum temperature of the PVT panel to 61.5 °C. Simultaneously, the average daily exergy efficiency and exergy efficiency of the PVT-TEG power generation system reached peak values of 21.06 % and 39.87 %, respectively. Compared to the reference PV panels, the output power of the PVT-TEG system increases by up to 30.51 %.

Study on the performance of semiconductor thermoelectric generator system driven by salt gradient solar pond

Study on the performance of semiconductor thermoelectric generator system driven by salt gradient solar pond

Study on the performance of semiconductor thermoelectric generator system driven by salt gradient solar pond

Study on the performance of semiconductor thermoelectric generator system driven by salt gradient solar pond

Numerical investigation of heat transfer mechanism in an embedded PCM-TEG for better overall performance under the fluctuating heat source

Using phase change materials (PCM) can effectively ensure the stable operation of semiconductor thermoelectric generators (TEGs). Conventional PCM-TEG structures exhibit relatively poor output performance due to energy barriers caused by low thermal conductivity. The embedded PCM-TEGs proposed in this study can address this issue well by adopting variable structure composite forms of PCM and TEG, resulting in a more complex heat transfer mode than traditional systems. To evaluate embedded systems' characteristics and performance enhancement methods, this paper first establishes a multiphysics mathematical model for embedded PCM-TEGs. Then, employing the TOPSIS method, an optimal embedded structure that considers system output and stability is obtained. Finally, we investigate the effects of key parameters on system performance, including PCM volume, latent heat, melting point, and metal-added composite materials. The CCC PCM-TEG (embedded PCM-TEG with PCM closer to the cold side) exhibits superior performance with a 28.6 % increase compared to conventional structures. For a given PCM volume, embedded structures with equal heights show better performance due to weak influence from asymmetric configurations on internal heat flow direction. Unlike traditional PCM-TEGs, metal-added composite PCMs in embedded structures reduce the temperature difference range across TEGs and thus deteriorate system performance.

Development of thermoelectric energy generator with high area density stacked polysilicon thermocouples

A semiconductor thermoelectric energy generator (TEG) with thermocouples in high area density is proposed in this work. Different from the common TEGs with co-planar thermocouples, the high area density is achieved by placing the P-thermoleg above the N-thermoleg into a stacked thermocouple, which is then insulated above and below by double cavity to retain sufficient thermal gradient. The TEG voltage factor is therefore increased by a factor of 2. For a TEG implemented by standard CMOS process (TSMC D35 2P4M), simulation shows that the stacked thermocouple of size 58 × 2 × 0.180 µm P-type thermoleg above 64 × 2 × 0.275 µm N-type thermoleg can reach optimal performance. Measurement results of a 5 × 5 mm2 TEG chip by semiconductor foundry service confirm the power factor of 0.075 μW/cm2K2 and the voltage factor of 7.004 V/cm2K are 1.7 x and 2.5 x, respectively, of that in TEG with co-planar thermocouples. This performance is the best of all TEGs with polysilicon thermocouples by standard CMOS process.

Heat transfer mechanism and structure design of phase change materials to improve thermoelectric device performance

In recent years, the use of phase change materials (PCM) to improve the output performance of semiconductor thermoelectric generators (TEG) and maintain the long-term work of TEG has received widespread attention. Because of the lack of a unified understanding of the existing PCM-TEG combination mode and PCM structure design, this paper first established a PCM-TEG coupling mathematical model, the accuracy of which is proved by experimental data. Secondly, for the three most common combinations of PCM and TEG, namely cold-sided, hot-sided and dual-sided PCM-TEG, the effect of PCM on TEG, the effect of finned PCM on system performance, and the system anti-interference ability when the heat source is unstable are respectively studied from the heat transfer mechanism. The results show that 1) PCM's high heat storage characteristics can effectively protect TEG and avoid device failure due to excessive temperature; 2) Designs of metal fins within PCM can effectively maintain advantages of the PCM and significantly enhance the temperature difference between the hot and cold ends of TEG, thereby significantly improving the system performance; 3) The cold-sided PCM-TEG system has the best output but the worst anti-interference ability compared to the hot-sided or dual-sided design. On a comprehensive basis, the dual-sided design is recommended in practice; 4) The cooling capacity of the PCM-TEG system significantly affects the performance. Enhancing the heat transfer coefficient of the cold end of the TEG can significantly improve PCM-TEG systems' performance.

Application of Thermoelectric Technology in Direct Air Cooling System of Thermal Power Plant

In recent years, with the improvement of the coefficient of merit of thermoelectric materials, the research of thermoelectric power generation has entered a new climax. The developed countries have listed the development of thermoelectric power generation technology into the medium and long-term energy development technology. The research on thermoelectric power generation in China started relatively late, mainly focusing on the theory and preparation of thermoelectric materials. At present, the field of semiconductor thermoelectric power generation is just introduced, and its practical application is still blank. Thermal power generation technology is used to recover waste heat from direct air cooling system of thermal power plant. Power supply of wireless temperature sensor can be realized through energy storage components or integrated power management system, which can reduce energy waste and environmental pollution. It is of great significance for industrial waste heat recovery and clean energy development.

Packaging of semiconductor thermoelectric energy generators with in-plane thermocouples and isolation cavities

With the advent of semiconductor foundry services, thermoelectric energy generator (TEG) by CMOS/BiCMOS process has been preferable for production yield, cost effectiveness, and device scalability. The thermocouples in semiconductor TEG often have thermal isolation cavity to reduce heat loss. Both die- and wafer-packaging are proposed in this work to seal the cavity, prevent moisture/dirt from contamination, and avoid short circuit condition in the thermocouples for TEG applications in wearable devices. For a TEG design by 3P6M (3 polysilicon layers and 6 metal layers) BiCMOS process, the die-level packaging by aluminum film of thickness 50 μm over the TEG is shown to be effective, though there is about 23 % temperature gradient loss by the packaging. The voltage factor is 18.22 V/cm2K, about 77 % of that before packaging. For a TEG design by 1P6M CMOS process, the wafer-level packaging by bonding two identical TEG device wafers is shown to have about 22 % loss in temperature gradient. Yet the TEG performance is increased significantly on the same footprint because of doubling area density, and hence doubling both the power factor and voltage factor. The power factor and voltage factor is 0.164 μW/cm2 K2 and 24.32 V/cm2K, respectively, on the TEG in series circuit after packaging.

A Thermoelectric Energy Harvester Based on Microstructured Quasicrystalline Solar Absorber.

As solar radiation is the most plentiful energy source on earth, thermoelectric energy harvesting emerges as an interesting solution for the Internet of Things (IoTs) in outdoor applications, particularly using semiconductor thermoelectric generators (TEGs) to power IoT devices. However, when a TEG is under solar radiation, the temperature gradient through TEG is minor, meaning that the TEG is useless. A method to keep a significant temperature gradient on a TEG is by using a solar absorber on one side for heating and a heat sink on the other side. In this paper, a compact TEG-based energy harvester that features a solar absorber based on a new class of solid matter, the so-called quasicrystal (QC), is presented. In addition, a water-cooled heat sink to improve the temperature gradient on the TEG is also proposed. The harvester is connected to a power management circuit that can provide an output voltage of 3 V and store up to 1.38 J in a supercapacitor per day. An experimental evaluation was carried out to compare the performance of the proposed QC-based harvester with another similar harvester but with a solar absorber based on conventional black paint. As a result, the QC-based harvester achieved 28.6% more efficient energy generation and achieved full charge of a supercapacitor around two hours earlier. At last, a study on how much the harvested energy can supply power to a sensor node for Smart agriculture during a day while considering a trade-off between the maximum number of measurements and the maximum number of transmission per day is presented.

Design of Comprehensive Utilization System of Semiconductor Thermal Power Generation

For the solar steam generation system, optical materials are obtained through experimental comparison and verification. A nanofluid material composed of a double-layer structure with a light absorber on the upper layer and an insulating material with two-dimensional or three-dimensional water transport channels on the lower layer is proposed, which is hydrophilic It uses capillary force and promotes fluid flow to the hot zone, and interconnected pores are used for fluid flow in and out of the structure. The device is embedded with a semiconductor thermoelectric power generation sheet in the lower layer, the upper surface is in contact with the photothermal layer, and the lower surface is in contact with bulk water. The temperature difference is formed and the electromotive force is generated, which makes the energy utilization efficiency higher.

A flexible, printable, thin-film thermoelectric generator based on reduced graphene oxide–carbon nanotubes composites

Thermoelectric energy harvesting is one of the keystones of modern green renewable energy generation. Unfortunately, most conventional state-of-the-art inorganic semiconductor thermoelectric generators are expensive, fragile, and not flexible. Considering these limitations, we developed a flexible printable thermoelectric generator (TEG) with both n-type and p-type organic composites of reduced graphene oxide, carbon nanotubes, poly(3,4-ethylenedixoythiphene)–polystyrene sulfate, and lead sulfide composite materials. We constructed a TEG of ten alternating n–p pairs as a prototype with an effective area of 1.4 cm2 each, which generated 13 mV thermovoltage at operating temperature difference of 77 °C. It demonstrates that its fabrication is scalable, printable, and relatively simple, and the resultant structure is flexible, conformal, and reconfigurable.

Review of Development Status of Bi2Te3‐Based Semiconductor Thermoelectric Power Generation

Semiconductor thermoelectric power generation is a new type of energy‐saving and environment‐friendly power generation technology, which directly converts heat energy into electrical energy by using the characteristics of semiconductor thermoelectric materials and has broad application prospects. This paper introduces the basic principles of thermoelectric materials and semiconductor thermoelectric power generation. The research status and progress of Bi2Te3‐based semiconductor materials and thermoelectric generators in recent years are also introduced, respectively. Then, the paper emphasizes the research status of low temperature difference semiconductor power generation and points out the future development directions.

Experimental study of the effects of the thermal contact resistance on the performance of thermoelectric generator

Semiconductor thermoelectric generation technology is promising for application to waste heat recovery and is increasingly attracting research interest. The objective of the present study was to determine how the performance of a thermoelectric generator (TEG) was affected by the thermal contact resistance. The effects of the interface material and loading pressure—factors that determine the thermal contact resistance—on the TEG performance were experimentally investigated and analyzed. It was found that, for a given temperature difference between the cold and hot sources, the actual temperature difference of the thermoelectric module and the output power significantly increased when an interface material was applied to the contact surface. In addition, with increasing loading pressure, there was a decrease in the thermal contact resistance between the two sides of the thermoelectric module, and an increase in both the actual temperature difference across the module and the output power. Further, for a given loading pressure, an increase in the thermal resistance of the thermoelectric module was accompanied by an increase in the average temperature of the module, a decrease in the ratio of the thermal contact resistance to the total thermal resistance, and an increase in the output power.

Experimental study on the influence of porous foam metal filled in the core flow region on the performance of thermoelectric generators

Semiconductor thermoelectric generator technology is a new type of power generation technology. The use of semiconductor thermoelectric power generation technology for automobile exhaust heat recovery and utilization can effectively improve energy efficiency. In this study, a test system is set up to simulate the automobile exhaust, and the effect of core flow heat-transfer enhancement on the performance of the thermoelectric generator is investigated using thermoelectric module Bi2Te3 to recover the waste heat from automobile exhaust and convert it into electrical energy. The results show that filling foam metal can significantly improve the performance of the generator. The convective heat-transfer coefficient of the channel increases by four times, and the output power of the thermoelectric generator is doubled when the intake flow rate is 120m3/h, the inlet temperature is 300°C, the pore density of the foam metal is 20 pores per inch, and the filling rate of the foam metal is 75%. In addition, the improvement in the performance of the generator is different under different intake air flows, different foam-metal filling rates, and different pore densities.

Thermoelectric Power Generation Using LNG Cold Energy and Flue Gas Heat

In this study, semiconductor thermoelectric power generation technology is applied to an LNG air-heated vaporizer. A new type of finned tube with a thermoelectric generation device is designed and the flue gas from natural gas combustion is introduced as the heat source to improve the power generation performance. The results indicate that a gasification tube with a flue gas heat source gives a gasification process of 2.02m, which is 15.8% of the value obtained with an air-heated gasification tube. In case of the vaporizer with a thermoelectric power generation device, an outside wall temperature of 42 °C ensures that frosting problems do not arise along the entire length. The power generation efficiency in the liquid-phase region and two-phase region is about 3.48%. Compared with the air-heated vaporizer with a thermoelectric power generation device, the length of gasification process for the proposed device decreased by 77.6%, while the total output increased by 3.24 times.

Experimental Study on the Influence of the Core Flow Heat Transfer Enhancement on the Performance of Thermoelectric Generator

Abstract Semiconductor thermoelectric generator technology has great potential in the field of recovery and utilization of waste heat from automobile exhaust gas. In this study, a test system is set up to simulate the automobile exhaust, and the effect of core flow heat transfer enhancement on the performance of thermoelectric generator is investigated using a thermoelectric module to recover the waste heat from automobile exhaust and to convert it into electrical energy.

Performance Evaluation of Waste Heat Recovery Systems Based on Semiconductor Thermoelectric Generators for Hypersonic Vehicles

The types and the characteristics of the waste heat on hypersonic vehicles and the application feasibility of thermoelectric generators (TEGs) for hypersonic aircraft are discussed in this paper. Two thermoelectric generator schemes with an isothermal heat source and a variable temperature heat source were proposed, and the corresponding models were developed to predict the performance of the waste heat recovery systems on a hypersonic vehicle with different heat sources. The thermoelectric efficiency variation with electric current, the temperature distribution of fuel and junctions, and the distribution of the thermoelectric figure of merit (ZT value) are described by diagrams. Besides, some improvements for a better performance are analyzed. The results indicate that the maximum values of thermoelectric efficiency are 5% and 2.5% for the isothermal heat source and the variable temperature heat source, respectively, and the thermoelectric efficiency improves with the temperature of the hot junction. The performance of the TEGs with variable temperature heat source is worse than that of the other TEGs under the same highest hot junction temperature conditions, and the former has a better conversion efficiency than the latter when the average temperatures are identical.

Retraction Notice: Research on Engine Exhaust Energy Recovery by a Heat Pipe Exchanger with a Semiconductor Thermoelectric Generator

Retraction Notice: Research on Engine Exhaust Energy Recovery by a Heat Pipe Exchanger with a Semiconductor Thermoelectric Generator

Retraction Notice: Research on Engine Exhaust Energy Recovery by a Heat Pipe Exchanger with a Semiconductor Thermoelectric Generator

Retraction Notice: Research on Engine Exhaust Energy Recovery by a Heat Pipe Exchanger with a Semiconductor Thermoelectric Generator

Effects of heat transfer characteristics between fluid channels and thermoelectric modules on optimal thermoelectric performance

Semiconductor thermoelectric generation technology has a promising application for waste heat recovery and is becoming a noticeable research field. This paper presents a mathematical thermoelectric generator (TEG) model applicable to engine exhaust gas heat recovery. This model considers the conduction along the heat exchanger and the contact thermal resistance of the exchanger plate between the fluid channel and the thermoelectric modules, which were neglected in a previous numerical analysis. Considering that there is an optimum module size corresponding to the maximum power output in a TEG system, the effects of heat transfer characteristics between the fluid channel and the thermoelectric modules on the optimal thermoelectric performance are investigated by using an engineering equation solver (EES) program. Numerical results show that there is a larger optimal area and a lower peak power when considering the conduction and contact thermal resistance factors mentioned above compared to traditional results, which are determined by considerably different factors such as internal heat transfer and temperature distributions. Moreover, an optimal thermal conductivity coefficient that corresponds to the peak power output exists when the conduction along the exchanger is considered. In the case when conduction along the exchanger is not considered, higher the thermal conductivity, the better is the thermoelectric performance. A thin-plate exchanger is recommended in the TEG system owing to its high power output. The optimal module area increases linearly, and the maximum power output exhibits an obvious decrease with an increase in the contact thermal resistance.