Based on the thermoelectric effect, a thermoelectric generator (TEG) converts heat directly into electricity. Because of no moving parts, it is very silent and highly reliable. 1 The classification of TEG According to the hot end temperature of TEG , it can be divided into three categories: high temperature TEG (more than 700℃), medium temperature TEG (between 400 and 700℃) and low temperature TEG (under 400℃). According to the usage heat source, there are four types of TEG: 1) radio isotop...(more)
Thermoelectric cooler is like a heat pump when its working, transferring heat from one point to another. This is not a common heat absorption process or a magic heat consumption process. When its powered on, one end of the TEC module will become cold while the other end hot. The cooled down end transfers the heat to the hot end, which conforms to the thermodynamics law. In order to complete a heat transfer process, the thermoelectric cooler needs to be connected to a proper heat sink, which is u...(more)
The material figure of merit Z is an important parameter to measure the cooling capacity of TEC and its expression is . In order to improve Z value, conductivity and Seebeck coefficient should be improved and thermal conductivity should be reduced. consists of phonon thermal conductivity p (about 90%) and electronic conductivity e. These three parameters are not independent of each other, which all are the function of carrier concentration n and temperature T. In the condition of different envir...(more)
Low dimensional thermoelectric (0~3D) material is a new research in recent years. Because of the function of the quantum well and quantum wire, low dimensional material has extraordinary thermoelectric property. The low dimension can increase and phonon boundary scattering of the potential well surface. Terry M Tritt obtained the different dimension curve of Bi 2 Te 3 with the change of quantum welldW(quantum wire thickness). The result shows that three dimensional material do not change with th...(more)
3 Thermoelectric materials In the view of the research and development of thermoelectric materials, lead telluride is used as a thermoelectric material in the early days, and then TAGS alloy is developed for P-type element (N-type is still PbTe). The temperature of the hot end can be up to 600℃. After using new thermoelectric materials in hundred watt thermoelectric generator and universal thermoelectric generator, the hot end temperature can reach 1000℃ and its mechanical properties and oxid...(more)
From (3), (13) and (14), it is shown that when T h - T c △ T max , the cooling capacity q c 0. At the same time, TEC cannot cool, but start heating, which is not allowed in practical work. So the working current should be controlled in range of I 0 I I sat , which can ensure the cooling capacity q c 0. Although based on the analysis of the cooling capacity q c , the general range of working current can be determined, but in practical work, the refrigeration coefficient is still an important ind...(more)
In actual applications, thermoelectric cooler includes two or more couples of semiconductor galvanic arms. Put electric and heat conductive inducer in series to make a single component. A TEC module is made up of one or multiple such single component in series from the view of current path, and in parallel from the view of heat path. The single component and inducer is generally installed between the two ceramic plates, which are used to connect all the parts mechanically, and keep every single ...(more)
The thermodynamic law can be applied to both TEC modules and traditional mechanical cooler. In mechanical cooling unit, use compressor to increase the liquid pressure, which enable the cryogen to circulate in the system. Then, the cryogen curs in the frozen area and then the temperature of the frozen area is reduced when the cryogen absorbs the heat during sublimation process. The heat absorbed by the cryogen is transferred to the compressor and then to the ambient environment through cryogen co...(more)
