Termoelektrický jev a jeho využití v procesním průmyslu

Abstract

Since thermoelectricity as a manifestation of several physical effect was discovered, it's utilization found it's way into many felds. While it is often not paid much attention in general, use of thermoelectric modules is getting more widespread. This is mainly due to increasing world-wide tendency of pursuing efficiency improvements across most of industrial branches. This thesis addresses a particular application of harvesting waste heat in form of exhaust ue gas using thermoelectric generators. Being introduced to thermoelectricity in general, examples of various historical and up-to-date applications of thermoelectric modules are given. After focusing on problematic of heat exchangers design, thesis dives into special branch of thermoelectric heat exchangers, being of fundamental importance for the construction of thermoelectric energy harvester. Mathematical tools are presented, allowing for description and optimization of such devices for particular applications. Numerical model is established using these equations, that is used for prototype device design. Most importantly, theoretical and model parts of the work are put into reality, resulting in fabrication of a simple thermoelectric heat exchanger prototype. The harvester was installed within waste incineration plant and it's performance was mon-itored and compared with predicted values. Several problematic spots of the design are high-lighted, such as unexpected heat transfer conditions or con icts between measured values and thermoelectric module data-sheet properties. Numerous reasons are presented to be possible cause of those deviations. Further actions are finally suggested to be taken, in order to achieve more precise predictions and optimize custom prototypes to follow.

Since thermoelectricity as a manifestation of several physical effect was discovered, it's utilization found it's way into many felds. While it is often not paid much attention in general, use of thermoelectric modules is getting more widespread. This is mainly due to increasing world-wide tendency of pursuing efficiency improvements across most of industrial branches. This thesis addresses a particular application of harvesting waste heat in form of exhaust ue gas using thermoelectric generators. Being introduced to thermoelectricity in general, examples of various historical and up-todate applications of thermoelectric modules are given. After focusing on problematic of heat exchangers design, thesis dives into special branch of thermoelectric heat exchangers, being of fundamental importance for the construction of thermoelectric energy harvester. Mathematical tools are presented, allowing for description and optimization of such devices for particular applications. Numerical model is established using these equations, that is used for prototype device design. Most importantly, theoretical and model parts of the work are put into reality, resulting in fabrication of a simple thermoelectric heat exchanger prototype. The harvester was installed within waste incineration plant and it's performance was monitored and compared with predicted values. Several problematic spots of the design are highlighted, such as unexpected heat transfer conditions or con icts between measured values and thermoelectric module data-sheet properties. Numerous reasons are presented to be possible cause of those deviations. Further actions are finally suggested to be taken, in order to achieve more precise predictions and optimize custom prototypes to follow.