Wyniki wyszukiwania - BazTech

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Investigation into Increasing the Motor-Drivable Current Using a Thermoelectric Cooling Module

Morikawa Kazuma, Katsura Seiichiro

Power Electronics and Drives

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2022

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Vol. 7 (42)

279--289

EN

To enhance the performance of humanoids, mobile robots and manipulators, motors are desired to be able to provide high torque without relying on gears. To be able to drive joint motors with high output, the current value that can flow needs to be increased. However, the heat generated by the high current drive can cause motor failure, so cooling is necessary. We used thermoelectric cooling as a new cooling method for high-power drive of motors. By developing a thermoelectric cooling module for motors and conducting experiments, the effectiveness of thermoelectric cooling was verified. In the experiment, the motor was kept running at a high current for a long period of time. The comparison with the motor alone or with water cooling showed that the thermoelectric cooling module can significantly reduce the rise in temperature of the motor. Furthermore, based on the results of the voltage value measurements, it was expected that the increase in coil resistance due to higher coil temperatures would be kept lower than in other cases. The effect on rise in internal temperature was also considered to be greater than that of water cooling. These experimental results show that the thermoelectric cooling module can be used to increase the upper limit of the current at which the motor is continuously driven.

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Investigation of waste heat recovery for automobile application based on a thermoelectric module

Buchalik R., Buczkowski D., Przybyła G., Nowak G.

Journal of KONES

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2016

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Vol. 23, No. 4

25--32

EN

The article presents a brief discussion about issues of energy harvesting of waste heat generated during the operation of the SI (spark ignition) internal combustion engine (ICE). The available methods of implementation and the problems associated with them were presented. In recent years, there has been an increase in the significance of successful researches on new types of thermoelectric modules. Despite relatively low efficiency of the thermoelectric modules, a systematic growth in their interest is observed. Their application seems to be reasonable because of many advantages - mainly the simplicity. The paper contains the literature review in the subject of interest. For the purpose of this work, a test rig was designed and manufactured. The test rig consists of a single thermoelectric module and makes it possible to work in variety of operating conditions for different values of the exhaust gas flow rate and temperature. It is equipped with an automatic, servo controlled, movable element, which control direction of the exhaust gas flow and as a result changes the heat flux transferred via the thermoelectric module. This solution allows achieving the maximum power of the thermoelectric module in a wide range of ICE operating conditions and also allows adjusting operating parameters to actual working conditions of the whole system. The problems encountered during the construction of the test rig and the proposed solutions of practical implementation were described. Experimental research was conducted on a small size automobile petrol engine. The influence of electrical parameters at the output on the whole system was analysed. The results suggest that the actual thermoelectric module parameters, especially the thermal conductivity, vary from declared by the producer. Maximum achieved electric power output reached about 10 W from a single thermoelectric module (57 mm x 54 mm), which is nearly half of the declared value.

3

Właściwości termoelektryczne lekkich zapraw budowlanych z dodatkiem odpadowego grafitu

Pichór W.

Materiały Ceramiczne

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2010

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T. 62, nr 2

161-165

PL

W pracy przedstawiono wyniki badań właściwości lekkich zapraw budowlanych, w których stwierdzono występowanie efektu termoelektrycznego. Niską gęstość pozorną zapraw cementowych uzyskano poprzez dodatek mikrosfer glinokrzemianowych, pozyskiwanych jako uboczny produkt spalania węgla kamiennego, zastępując nimi część piasku. Jako dodatek przewodzący wykorzystano grafitowy pył powstający w czasie szlifowania elektrod przeznaczonych dla przemysłu metalurgicznego. Zbadano wpływ ilości mikrosfer oraz ilości grafitu odpadowego na podstawowe właściwości użytkowe lekkich zapraw cementowych, przede wszystkim współczynnik przewodzenia ciepła oraz wytrzymałość. Zmierzono również napięcie termoelektryczne generowane poprzez zaprawy z dodatkiem 35% grafitu w zakresie temperatur -10 do 50°C. Wprowadzenie grafitu w stosunkowo dużych ilościach powodowało umiarkowane pogorszenie właściwości termoizolacyjnych i wytrzymałościowych zapraw, jednak kompozyty takie wykazywały zdolność generacji napięcia termoelektrycznego proporcjonalnego do temperatury (efekt Seebecka). Niska wartość współczynnika przewodzenia ciepła zapraw pozwala uzyskać stosunkowo duży gradient temperatury w cienkiej warstwie materiału, dzięki czemu możliwe staje się wykorzystanie słabego efektu Seebecka. Zaprawy takie dzięki swojej wielofunkcyjności mogą zatem znaleźć zastosowanie w konstrukcjach tzw. domów inteligentnych, do monitoringu temperatury przegród budowlanych.

EN

This paper presents the results of investigation of physical and thermoelectric properties of lightweight cement mortars with cenospheres from coal ash and waste graphite powder additive. Quartz sand was replaced by the aluminosilicate cenospheres up to 60% of mass. The sand replacement led to the significant reduction of bulk density and thermal conductivity of the cement mortars. The waste graphite powder obtained during mechanical treatment of electrodes for the metallurgical industry was used as a conductive filler. It was added up to 35% of cement mass. The main physical properties i.e. bulk density, thermal conductivity, and bending strength were investigated. In case of the mortars with the 35% replacement of cement by graphite, the Seebeck voltage was measured. Addition of the graphite powder to mortars led to the moderate deterioration of main properties but the cement mortars received possibility of thermoelectric reaction due to the temperature changes. The Seebeck coefficients calculated for all investigated mortars were similar (in the error range) and, in each case, weak dependence of temperature gradient was visible. But in typical application, the thickness of used mortars was very small (about 1-2 cm) and the changes were too small to induce measurable level of the thermoelectric force. The point is that in case of lightweight mortars the low thermal conductivity caused much higher temperature gradient and as a consequence the Seebeck voltage increased. Lightweight cement mortars with conductive particles originated from the graphite powder are the multifunctional materials and may be used to monitor the temperature of building walls.