THE MATHEMATICAL MODEL OF THE HEAT EXCHANGE PROCESS IN THERMOELECTRIC GENERATOR DESIGNED FOR RECOVERY OF ENERGY OF DOMESTIC HEATING OVEN

Abstract

Declining stocks of fossil fuels in the world and its rise in price for consumers makes it necessary to reduce the cost of energy consumption of buildings. In Ukrainian villages, in most cases, rough heating is used. Therefore, it is important to ensure the production of electricity through the use of a thermoelectric generator (TEG), which connects to the chimney and uses the energy of flue gases. As a result, the house will generate electricity during the heating season and can be virtually independent of this type of energy. Despite the fact that there is a significant amount of research on thermoelectric materials, the operation of various heat exchangers, different designs of TEG (including a description of the rules of their design), the mathematical model of direct use of exhaust gas energy in a household stove burning biomass is still absent. . The paper considers a mathematical model of the heat exchange process during the use of TEG for utilization of residual energy of flue gases of a household furnace, which allows to obtain electric energy for domestic consumption. The thermoelectric module manufactured by the Ukrainian company Altek-1024 was chosen as the basis of the generator. According to a certain design of the thermoelectric generator, a thermal calculation was performed on the basis of the heat balance equations. A system of two equations for the transfer of flue gas energy through the TEM surface was obtained. The solution of this system, taking into account the temperature dependence of the main characteristics of flue gases, such as density, specific heat, thermal conductivity, made it possible to obtain the dependence of thermal energy extraction power on the inner surface area of the generator. From the obtained dependence it follows that the use of Altek-1024 modules in the amount of 3 pieces makes it possible to extract power from the flue gases of about 1 kW. The corresponding estimated amount of electrical energy is 100 watts. This value, on average, exceeds the minimum rate of electricity consumption of an individual house.