scholarly journals Cu2Se-based thermoelectric cellular architectures for efficient and durable power generation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Seungjun Choo ◽  
Faizan Ejaz ◽  
Hyejin Ju ◽  
Fredrick Kim ◽  
Jungsoo Lee ◽  
...  

AbstractThermoelectric power generation offers a promising way to recover waste heat. The geometrical design of thermoelectric legs in modules is important to ensure sustainable power generation but cannot be easily achieved by traditional fabrication processes. Herein, we propose the design of cellular thermoelectric architectures for efficient and durable power generation, realized by the extrusion-based 3D printing process of Cu2Se thermoelectric materials. We design the optimum aspect ratio of a cuboid thermoelectric leg to maximize the power output and extend this design to the mechanically stiff cellular architectures of hollow hexagonal column- and honeycomb-based thermoelectric legs. Moreover, we develop organic binder-free Cu2Se-based 3D-printing inks with desirable viscoelasticity, tailored with an additive of inorganic Se82− polyanion, fabricating the designed topologies. The computational simulation and experimental measurement demonstrate the superior power output and mechanical stiffness of the proposed cellular thermoelectric architectures to other designs, unveiling the importance of topological designs of thermoelectric legs toward higher power and longer durability.

2021 ◽  
Author(s):  
Seungjun Choo ◽  
Faizan Ejaz ◽  
Hyejin Ju ◽  
Fredrick Kim ◽  
Jungsoo Lee ◽  
...  

Abstract Thermoelectric (TE) power generation offers a promising way to recover waste heat. The geometrical design of TE legs in modules is important to ensure sustainable power generation but cannot be easily achieved by traditional fabrication processes. Herein, we propose the design of cellular TE architectures for efficient and durable power generation, realized by the extrusion-based 3D printing process of Cu2Se TE materials. We designed the optimum aspect ratio of a cuboid TE leg to maximize the power output and extended this design to the mechanically stiff cellular architectures of hollow hexagonal column- and honeycomb-based TE legs. Moreover, we developed organic binder-free Cu2Se-based 3D-printing inks with desirable viscoelasticity, tailored with an additive of inorganic Se82- polyanion, fabricating the designed topologies. The computational simulation and experimental measurement demonstrated the superior power output and mechanical stiffness of the proposed cellular TE architectures to other designs, unveiling the importance of topological designs of TE legs toward higher power and longer durability.


Author(s):  
Maclain M. Holton ◽  
Michael S. Klassen ◽  
Leo D. Eskin ◽  
Richard J. Joklik ◽  
Richard J. Roby

Nearly all states now have renewable portfolio standards (RPS) requiring electricity suppliers to produce a certain fraction of their electricity using renewable sources. Many renewable energy technologies have been developed to contribute to RPS requirements, but these technologies lack the advantage of being a dispatchable source which would give a grid operator the ability to quickly augment power output on demand. Gas turbines burning biofuels can meet the need of being dispatchable while using renewable fuels. However, traditional combustion of liquid fuels would not meet the pollution levels of modern dry, low emission (DLE) gas turbines burning natural gas without extensive back-end clean-up. A Lean, Premixed, Prevaporized (LPP) combustion technology has been developed to vaporize liquid ethanol and blend it with natural gas creating a mixture which can be burned in practically any combustion device in place of ordinary natural gas. The LPP technology delivers a clean-burning gas which is able to fuel a gas turbine engine with no alterations made to the combustor hardware. Further, the fraction of ethanol blended in the LPP gas can be quickly modulated to maintain the supplier’s overall renewable quotient to balance fluctuations in power output of less reliable renewable power sources such as wind and solar. The LPP technology has successfully demonstrated over 1,000 hours of dispatchable power generation on a 30 kW Capstone C30 microturbine using vaporized liquid fuels. The full range of fuel mixtures ranging from 100% methane with no ethanol addition to 100% ethanol with no methane addition have been burned in the demonstration engine. Emissions from ethanol/natural gas mixtures have been comparable to baseline natural gas emissions of 3 ppm NOx and 30 ppm CO. Waste heat from the combustor exhaust is recovered in an indirect heat exchanger and is used to vaporize the ethanol as it is blended with natural gas. This design allows for startup on natural gas and blending of vaporized ethanol once the heat exchanger has reached its operating temperature.


RSC Advances ◽  
2015 ◽  
Vol 5 (103) ◽  
pp. 85073-85081 ◽  
Author(s):  
Cheng-Tang Pan ◽  
Chung-Kun Yen ◽  
Shao-Yu Wang ◽  
Yan-Cheng Lai ◽  
Liwei Lin ◽  
...  

The power generation of the piezoelectric PVDF fiber tubes was 2.46 times higher than that of the solid fibers, which not only displayed mechanical stiffness but also produced a greater power output.


Author(s):  
Stephan Arnold ◽  
Markus Schatz

Combined heat and power generation (CHP) is a way of providing both electric power and thermal heat for industrial and domestic facilities at high fuel efficiencies. Often small and medium sized gas powered internal combustion (IC) engines, rated at electric power outputs of 50–600 kW, are used for such applications. During the time when the available thermal heat is used, the fuel efficiency of such CHP plants is very high, but it drops to the efficiencies of simple power generation when there is no heat demand, e.g. during summer. In these cases, the exhaust heat is blown off, especially as CHP units are mainly heat-lead, i.e. designed to cover the heat demand rather than the demand for electrical power. Moreover, as the cooling water heat rejection is also more difficult at elevated ambient temperatures, these units are then operated at part load or even switched off, hence having a lower degree of capacity utilization. The approach of the work presented here is to replace the turbocharger system commonly used for IC engines and to use an electric driven compression device instead, while the turbine serves to generate additional electric power from the exhaust gas. Furthermore, for periods with low thermal heat demand, steam is generated from the turbine exhaust heat. The steam is injected in front of the turbine in order to increase the turbine work output further. Thus, at least part of the exhaust heat available is used and the power output as well as the electric efficiency is increased. In the present work, two configurations of the described setup using a medium sized gas powered IC engine CHP unit are modeled in order to assess the impact on plant performance and the characteristics of such a facility. In both cases the engine cooling circuit is integrated. Depending on the configuration used, the plant power output increases by up to 7% only because of the power turbine. Additional steam injection to use the waste heat increases the power output further. The relative electric efficiency increase with steam injection is in the range of 3–5%. Apart from the higher output of electric power, this approach allows longer operating hours to be achieved, as the exhaust heat available is utilized and the heat load for the cooling water circuit is reduced.


RSC Advances ◽  
2017 ◽  
Vol 7 (18) ◽  
pp. 10707-10717 ◽  
Author(s):  
Ghosh Ray ◽  
Md. T. Noori ◽  
M. M. Ghangrekar

A major limitation to achieving higher power output from microbial fuel cells (MFC) is the competitive environment for substrate utilization offered by methanogenic archaea.


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