RELATIONSHIP OF NON-EQUILIBRIUM THERMODYNAMICS IN THE HETEROGENEOUS PERMEABLE THERMOELEMENTS
Authors:   Yurii Fedkovych Chernivtsi National University, Ukraine, Semeshkin Vitalii , Cherkez Radion ,   Yurii Fedkovych Chernivtsi National University, Ukraine
Published: December 2023

A significant number of thermoelectric processes are described with fundamental law of thermodynamics. This paper describes thermoelectric processes in the permeable thermoelements, which are described with the help of relationships of non-equilibrium thermodynamics. The thermoelectric effects, which are described in this work, are laid in the basis of the work of thermoelectric elements, which make up the modules of generators and coolers. Any thermoelectric module can work in refrigerating regime as well as in generator regime. The difference is that, in order to generate energy and to work in the refrigerating regime, the different temperatures and different semiconductors are optimal, which are used in development of thermoelectric modules. The heterogenous materials, which are used to create new thermoelectric modules, can be defined as materials with different sharp heterogeneity of durability from one phase to the other. This heterogeneity of durability may be caused by microstructure of diversity, heterogeneity of the crystal structure or compositional diversity. The size of phases may be in the range from micrometers to millimeters, the geometry of phases may change and create different material systems. The object of this research is the processes in non-equilibrium thermodynamic systems. The subject of the research is the flow of thermodynamic processes in heterogeneous materials, relationship of non-equilibrium thermodynamics in the heterogeneous permeable thermoelements. The methodology of the research is based on the common scientific methods of analysis and synthesis, induction and deduction, observation and abstraction, which are used to systemize results and calculations of thermoelectric systems. The aim of the work is familiarization with the relationship of non-equilibrium thermodynamics, its systematization and calculation of optimal parameters of permeable thermoelement on its basis. This paper describes the physical nature of thermodynamic and thermoelectric phenomenon, based on the newest actual and classic works of the branch of thermoelectricity, non-equilibrium thermodynamics, applied and thermoelectric material science, and their practical application. The analytical review of the literature about the problematics of non-equilibrium thermodynamics in heterogeneous systems was done. We observed the advantages and disadvantages of these systems. The practical part of this work consists of the calculation of parameters of permeable thermoelement made of thermoelectric material on the base of BismuthTtelluride for thermoelectric cooler or, as it used to say in the field of thermoelectricity, thermoelectric heat pump, calculation of dependence of its parameters on amount and size of channels of permeable thermoelement. While investigating the relationship of non-equilibrium thermodynamics, exactly Gibbs’ equation, Boltzmann’s equation, the equation of coolant and heat flow, equation of cooling coefficient, we systemized them and calculated the optimal parameters for the permeable thermoelectric element of cooling on the base of diverse semiconducting alloy Bi2Te3. On the basis of these calculations, we graphically represented the dependence of parameters of semiconducting permeable thermoelectric element on width of its channel, showed optimal definition of width of channel of permeable thermoelectric element. The results of research showed that, by means of the system of channels with the heat carrier, which make changes in the gradient and the temperature’s distribution on the element, is the significant advantage of the cooling factor of the thermoelectric electric over impenetrable.