International Journal of Intelligent Systems and Applications in Engineering ISSN:2147-67992147-6799 www.ijisae.org Original Research Paper International Journal of Intelligent Systems and Applications in Engineering IJISAE, 2018, 6(1), 65-71 |65 The Effects of Speed and Flow Rate on Power in Thermoelectric Generators Abdullah Cem AGACAYAK 1 , Hakan TERZIOGLU* 1 , Hasan CIMEN 2 , Suleyman NESELI 3 , Gokhan YALCIN 3 Accepted : 12/02/2018 Published: 30/03/2018 x Abstract: Geothermal energy is a kind of clean energy which has existed since the world existed. Every passing year new geotermal fields are invented and their area of usage is increasing rapidly. In our day, where there is tendency of rising in the energy costs; the geothermal energy rise in importance as an alternative resource. Therefore, in this study the design of the thermoelectric generator which directly transforms the geothermal energy that is one of the renewable energy sources to electrical energy and the execution of the system is carried out. In the system, two different types of TEC1-12706 and TEC1-12710 thermoelectric moduls which are made up of thermoelectric semi- conductors that can be easily acquired in the markets are used in the energy transition. In the experimental studies that are performed, the power rating which thermalelectric generators produce in 3 different pressure and 3 different flow rate of hot and cold water are compared. Consequently, it is seen that the speed and the flow rate of the water is efficacious on the power which thermoelectric generators generate. Keywords: Electricity Generation; Renewable Energy; Thermoelectric Generator; Thermoelectric Modul; Termal Performance. 1. Introduction Energy needs and demands are increasing constantly in many countries around the world, especially in the developing countries like Turkey. While the development of technology and industry increases energy consumption on one side, it increases the damage to the environment on the other side. With the increase in environmental and energy problems, there has also been an increase in the studies carried out in recent years on energy production and its impacts on the environment around the world. With the developing technology, efforts are being made to obtain efficient, cheap and clean energy from alternative energy sources. When these studies and the environmental and economic effects of the global electricity generation systems are taken into consideration, renewable energy sources from alternative energy sources come to the forefront. Resources used as renewable energy resources in the world include geothermal energy, solar energy, wind energy, biomass energy, hydrogen energy, tidal energy generated by sea waves. Renewable energy sources other than geothermal energy have some disadvantages. These sources have negative environmental impacts though not as much as fossil sources. They can only be used at certain times of the year and therefore they cannot produce energy constantly. Their technologies are not fully developed, and their costs are expensive [1;2;3;5]. Therefore, scientists are looking for alternative energy sources such as geothermal energy etc. that do not have negative impacts on the environment, that can be used at any time of the year and that are cost-effective. With the increasing interest in geothermal energy in recent years, the importance of thermoelectric (TE) semiconductors and related technologies has also increased. Thermoelectric modules (TEM) have many advantages. They are long lasting, do not need maintenance, quiet, they do not have moving parts, they are reliable and have simple structures. Due to these advantages, interest in the TEMs is increasing day by day [16]. If DC voltages are applied to the ends of the TEMs, the electrons in the P-N semiconductors in their structures will move. As a result of this movement of the electrons, one surface of the TEMs is heated while the other surface is cooled. If we run this module reversed to create a temperature difference between the surfaces, modules operate as a thermoelectric generator (TEG) and we obtain DC voltage from their terminals. The more the temperature difference between the surfaces, the more electrical energy production increases. It is difficult to obtain a constant voltage because the temperature difference on the TEM surfaces depends on the sources used and these temperatures can vary over time. Therefore, for constant voltage, DC voltage needs to be stored and regulated [16]. The studies that have been carried out on this subject so far are: Kinsella et al. produced electricity using the heat of the liquid flowing with a single thermoelectric generator (TEG) that produces low electrical current and also developed a prototype electric generator to store this energy produced. They charged a 3.3 V lithium-iron-phosphate battery, which can be charged with TEG-generated electricity [13]. Atik et al. heated one surface of 8 thermoelectric modules with hot water and cooled the other surface with tap water. With the temperature difference of 70 °C, they obtained; they obtained 6V electric power and 2.5W power [6]. Fettah used the waste heat generated during operation of the solid oxide fuel battery in his work. In this study, by demonstrating the operability of a system that generates electricity using thermoelectric modules, he intended to set an example for future work. In practice, he compared water-cooled and air-cooled systems. When the Seebeck effect and the flow relation are examined, he stated that the heat convection coefficient of the air increases with the turbulent flow when the flow increases [10]. _______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 1 Electrical Prog., Selcuk University, Konya – 42002, Turkey 2 Elec./Electronic Engg., Selcuk University, Konya – 42002, Turkey 3 Mechanical Engg., Selcuk University, Konya – 42002, Turkey * Corresponding Author: Email: hterzioglu@selcuk.edu.tr