DAMPING OF THERMAL STRESSES IN THERMOELECTRIC MODULES OF SHIP ELECTRICAL EQUIPMENT

Abstract

The research is related to the urgent issues of reducing to an acceptable level thermal stresses in the thermoelectric modules of the ship's electrical equipment. Thermal stresses arise in them due to thermal deformations in thermoelectric materials as a result of their simultaneous expansion and contraction during the thermoelectric effect. Based on the three created models of thermoelectric elements by connecting them into a thermoelectric circuit in the form of a U-shaped snake, three models of the corresponding thermoelectric modules were formed. One module had a classic design without damping, and the other two had single-layer damping inserts made of ductile material. Each of these thermoelectric modules consisted of a thermoelectric chain of 39 semiconductor P-N-thermocouples, contained 20 P-type semiconductors and 20 N-type semiconductors, 41 contact commutation plates. The overall dimensions (excluding the thickness of the insulating case) of the designed thermoelectric modules of the classic design without damping and designs with large and small dampers were 30×25.5×7 mm and 30×25.5×8 mm, respectively. The outer surfaces of the thermoelectric modules were considered adiabatically heat-insulated for the study of these devices in more stressful modes of operation and for evaluating the influence of maximum thermal stresses on them. According to the results of the calculation, the distribution of the main operating parameters by volume of thermoelectric modules was obtained. The operating characteristics of the thermoelectric modules of the ship's electrical equipment at variations of the operating current from 0 to 3 A for current density j, voltage U, electric field strength E, temperature on the hot side t, heat flux density q, ohmic heating J, equivalent stress σ and deformations ε. Based on the obtained results, the best design of the thermoelectric module was chosen, in which the damper inserts effectively reduce the level of thermal stresses. The advantages of using modern numerical calculation methods for solving field problems in the design of ship electrical equipment are shown.