• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.26 no.7
• /
• pp.329-334
• /
• 2014

This study indicated the possibility of energy regeneration from waste coolant heat, by using thermoelectric generation integrated with heat pipe. The internal combustion engine rejects more than 60% wasteful energy to the atmosphere by heat. The thermoelectric generator has recently been studied, to convert the energy from engine waste heat into electricity. For coolant waste heat recovery, a thermoelectric generator was investigated, to find out the possibility of vehicular application. Performance characteristics were conducted with various test conditions of coolant temperature, coolant mass flow rate, air temperature, and air velocity, with the thermoelectric generator installed either horizontally or vertically. Experimental results show that the electric power and conversion efficiency increases according to the temperature difference between the hot and cold side of the thermoelectric generator, and the coolant flow rate of the hot side heat exchanger. Performance improvement can be expected by optimizing the heat pipe design.

• Journal of Power Electronics
• /
• v.10 no.2
• /
• pp.187-193
• /
• 2010

This paper proposes a cooling system using thermoelectric elements for improving the output of building integrated photovoltaic (BIPV) modules. The temperature characteristics that improve the output of a BIPV system have rarely been studied up to now but some researchers have proposed a method using a ventilator. The efficiency of a ventilator depends mainly on the weather such as wind, irradiation etc. Because this cooling system is so sensitive to the velocity of the wind, it is unable to operate in the nominal operating cell temperature (NOCT) or the standard test condition (STC) which allow it to generate the maximum output. This paper proposes a cooling system using thermoelectric elements to solve such problems. The temperature control of thermoelectric elements can be controlled independently in an outdoor environment because it is performed by a micro-controller. In addition, it can be operated around the NOCT or the STC through an algorithm for temperature control. Therefore, the output of the system is increased and the efficiency is raised. This paper proves the validity of the proposed method by comparing the data obtained through experiments on the cooling systems of BIPV modules using a ventilator and thermoelectric elements.

• Applied Chemistry for Engineering
• /
• v.27 no.4
• /
• pp.353-357
• /
• 2016

Following the population growth and civilization, resulted in energy-mass consumption society, research efforts on enhancing efficiency of traditional energy sources has been investigated. Among many alternatives, thermoelectric power generation technologies are highlighted as one of solutions for high heat energy efficiencies. Currently, the research area of thermoelectric power generation has been achieved over two of ZT value, which seems to have enough competitiveness as following the development of nano-technologies, in particular, for waste heat recovery, and the development of thermoelectric materials is still ongoing to obtain higher energy efficiencies. In this review, the recent development of thermoelectric materials and module technologies categorized by different temperature regions was briefly introduced.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.22 no.5
• /
• pp.443-447
• /
• 2009

Bismuth-antimony-telluride based thermoelectric thin film materials were prepared by metal organic vapor phase deposition using trimethylbismuth, triethylantimony and diisopropyltelluride as metal organic sources. A planar type thermoelectric device has been fabricated using p-type $Bi_{0.4}Sb_{1.6}Te_3$ and n-type $Bi_{2}Te_{3}$ thin films. Firstly, the p-type thermoelectric element was patterned after growth of $5{\mu}m$ thickness of $Bi_{0.4}Sb_{1.6}Te_3$ layer. Again n-type $Bi_{2}Te_{3}$ film was grown onto the patterned p-type thermoelectric film and n-type strips are formed by using selective chemical etchant for $Bi_{2}Te_{3}$. The top electrical connector was formed by thermally deposited metal film. The generator consists of 20 pairs of p- and n-type legs. We demonstrate complex structures of different conduction types of thermoelectric element on same substrate by two separate runs of MOCVD with etch-stop layer and selective etchant for n-type thermoelectric material. Device performance was evaluated on a number of thermoelectric devices. To demonstrate power generation, one side of the device was heated by heating block and the voltage output was measured. The highest estimated power of 1.3 ${\mu}m$ is obtained at the temperature difference of 45 K.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.10a
• /
• pp.481-482
• /
• 2012

• Proceedings of the KWS Conference
• /
• 2005.06a
• /
• pp.144-146
• /
• 2005

Measurements of Thermoelectric power (TEP) were used to evaluate microstructural analysis in HSLA steel weldments. The measurements of TEP for weld microstructure across weldment have shown good correlation with hardness profile. The different TEP values indicated that changes in weld microstructure can be correlated with TEP values measured.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.22 no.5
• /
• pp.259-267
• /
• 2010

An experiment has been performed in order to investigate the characteristics of multiple thermoelectric modules (TEMs) with electrical circuits. The open circuit voltage of TEM connected parallel circuit is equal to the sum of individual TEMs. In contrast, the open circuit voltage is equal to the average of that individual TEM for a series circuit. The power output and conversion efficiency of TEM for both parallel and series circuits increase as the operating temperature conditions for individual TEMs becomes identical. Comparing parallel with series circuits, the power generation performance is more excellent for series circuit than parallel circuit. This result is attributed to the power loss from the TEM with better power generation performance.

• Korean Journal of Metals and Materials
• /
• v.47 no.4
• /
• pp.248-255
• /
• 2009

A micro thermoelectric device was processed by electroplating the n-type Bi-Te nanowires and ptype Sb-Te nanowires into an alumina template with 200 nm pores. Power generation characteristics of the micro devices composed of the Bi-Te nanowires, the Sb-Te nanowires, and both the Bi-Te and the Sb-Te nanowires were analyzed with applying a temperature difference of $40^{\circ}C$ across the devices along the thickness direction. The n-type Bi-Te and the p-type Sb-Te nanowire devices exhibited thermoelectric power outputs of $3.8{\times}10^{-10}W$ and $4.8{\times}10^{-10}W$, respectively. The output power of the device composed of both the Bi-Te and the Sb-Te nanowires decreased to $1.4{\times}10^{-10}W$ due to a large electrical resistance of the Cu electrode connecting the Bi-Te nanowire array with the Sb-Te nanowire array.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.05a
• /
• pp.460-463
• /
• 2008

A large part of the overall industrial energy is dissipated as waste heat despite of much development in the utilization of thermal energy. A mean efficiency is reported to be only around 30 to 35%. The existing waste heat recovery technology has reached its limit and consequently, the development of a new technology is necessary. Improving efficiency using thermoelectric technology has recently come into the spotlight because of its unique way to recover thermal energy. In fact, thermoelectric generator directly converts thermal energy into electric energy by a solid state without any moving parts. Futhermore remarkable improvement in the thermoelectric energy conversion efficiency has been achieved. In this study, a thermoelectric generator was made using commercialized thermoelectric modules. With thermoelectric modules attached on a duct surface, hot air was blown into the duct using a hot air blower. On the other side of the module, a water jacket was attached to cool the module. With different air inlet temperatures and water flowrates, the electrical power of the thermoelectric generator was measured.

• Journal of the Korean Ceramic Society
• /
• v.37 no.5
• /
• pp.432-437
• /
• 2000

Thermoelectric properties of p-type SiGe alloys prepared by a RF inductive furnace were investigated. Non-doped Si80Ge20 alloys were fabricated by control of the quantity of volatile Ge. The carrier of p-type SiGe alloy was controlled by B-doping. B doped p-type SiGe alloys were synthesized by melting the mixture of Ge and Si containing B. The effects of sintering/annealing conditions and compaction pressure on thermoelectric properties (electrical conductivity and Seebeck coefficient) were investigated. For nondoped SiGe alloys, electrical conductivity increased with increasing temperatures and Seebeck coefficient was measured negative showing a typical n-type semiconductivity. On the other hand, B-doped SiGe alloys exhibited positive Seebeck coefficient and their electrical conductivity decreased with increasing temperatures. Thermoelectric properties were more sensitive to compaction pressure than annealing time. The highest power factor obtained in this work was 8.89${\times}$10-6J/cm$.$K2$.$s for 1 at% B-doped SiGe alloy.