Results 1 - 10 of 1993
Results 1 - 10 of 1993. Search took: 0.024 seconds
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[en] In this paper we analyze the thermodynamic efficiency expected for a fully dissipative thermoelectric generator (TEG) operating under stationary conditions at a finite rate. Although a finite-time thermodynamic analysis of TEGs has been aimed at since long time, no complete theory is available yet. The state of the art of theory is reviewed, and a simple expression for the maximum achievable efficiency of TEGs operating under fully irreversible conditions is obtained. This also sets a reference efficiency for forthcoming studies of nonstationary operation of TEGs.
[en] We comment on the value and nature of terms contributing to the Seebeck coefficient of a thermoelectric cell. Transported entropies of ions can be connected with thermodynamic entropies, but they cannot be compared directly to partial molar properties of ions, as they are transport properties, rather than equilibrium properties. Equilibrium thermodynamics is contained in the more general non-equilibrium thermodynamic theory as a special case, apart from that the two cannot be unified
[en] The thermoelectric phenomena, their physical principle and the application thereof in thermoelectric generators are discussed. The requirements placed on the material and the technological problems of the construction of thermoelectric generators are outlined
[en] Electrical degradation experienced during production of the MC2730 Radioisotopic Thermoelectric Generator has led to a study of the cause of the degradation and review of the procedures used to clean the thermopiles. By comparing data obtained electrically with that obtained by scanning Auger microprobe analysis, a surface carbon layer was identified as the cause of the degradation. Ion sputtering removal of the carbon layer resulted in recovered electrical properties. Chemical, UV and plasma cleaning were studied to determine their effectiveness in removing photoresist from the thermopiles. The most effective procedure was a combination of chemical and UV cleaning. This procedure was shown to be far more effective than chemical cleaning by itself and was able to reduce the carbon levels to levels which were nearly nondetectable by Auger electron spectroscopy
[en] Highlights: • Flexible thermoelectric generators are screen printed with low cost metallic inks. • Thermoelectric generators are integrated into radial pipe insulation. • 15 cm section of pipe insulation is used to power a wireless sensing circuit. • Electrical configuration of thermoelectric device is optimized for a D.C. to D.C. converter. - Abstract: The Internet of Things (IoT), coupled with advanced analytics, is poised to revolutionize manufacturing maintenance and efficiency. However, a practical route to powering these many IoT devices remains unclear. In this work, flexible thermoelectric generators (TEGs) are fabricated from low cost, screen printed silver and nickel inks before being integrated into a novel form factor device based on commercial steam pipe insulation. Through optimization of internal resistances and total device design, this 420-junction TEG device produces 308 µW of power at a temperature difference of 127 K. This is sufficient to power a temperature sensing circuit with wireless communication capabilities. In this report we demonstrate that, after an initial 4 h of charging, this TEG can power a standard RFduino microcontroller for 10 min while sending temperature readings every 30 s via Bluetooth Low Energy (BLE) to a cell phone. Additional optimization and scaling could further increase system efficiency and provide a viable route to powering an industrial wireless sensing network (WSN).