The Importance of the Assembly in Thermoelectric Generators

Abstract

Generally, in the optimization of thermoelectric generators, only the heat exchangers or the thermoelectric modules themselves are taken into account. However, the assembly of the generator as a whole is of vital importance since a bad contact or a thermal bridge can waste the performance of an optimal generator. In this sense, the present chapter analyzes experimentally the use of different interface materials to reduce the thermal contact resistance between the modules and the heat exchangers, the influence of the pressure distribution in the assembly as well as the effect of different insulating materials in order to reduce the thermal bridge between the exchangers. Thus, it has been demonstrated that a good assembly requires the implementation of thermal interface materials to ensure the microscopic contact between the heat exchangers and the modules, besides a uniform clamping pressure. Nevertheless, since this is normally achieved with screws, they represent a source of thermal bridges in conjunction with the small distance between the exchangers. In order to reduce heat losses due to thermal bridges, which can represent up to one-third of the incoming heat, an increment of the distance between the exchangers and the use of an insulator is recommended.

Improvements in the cooling capacity and the COP of a transcritical CO2 refrigeration plant operating with a thermoelectric subcooling system

“…With respect air dissipation, a phase change heat exchanger, a heat-pipe, has been considered. In all cases, the bond interface between the TEMs and the heat exchangers is filled with a highthermal conductivity material in order to minimize the thermal resistance as was studied by [41] and the gap not occupied by the modules is filled with an insulation material with a thermal conductivity of 0.09 W/m•K and a thickness of 10 mm.…”

Prospects of Autonomous Volcanic Monitoring Stations: Experimental Investigation on Thermoelectric Generation from Fumaroles

“…Firstly, it can be observed that the introduction of the heat extender causes a slight temperature loss in the hot side of the thermoelectric module, which is quantified at an average of 3 . In the case of not introducing it, the temperature of the hot side of the thermoelectric modules would slightly increase, but heat losses through thermal bridges will be higher, reducing total efficiency [ 49 ].…”

“…The only difference between them is that the latter is sealed with silicone for protection. Furthermore, as shown in Figure 1 , a 40 × 40 × 10 aluminum heat extender was added between the hot side heat exchanger and each thermoelectric module since a slight separation of the heat exchangers reduces thermal losses due to thermal bridges [ 49 ].…”

Experimental Evidence of the Viability of Thermoelectric Generators to Power Volcanic Monitoring Stations

“…The hot and cold heat exchangers are assembled by means of four M5 threaded rods, which due to their closeness, ensure a good pressure distribution in the thermoelectric modules and therefore a suitable thermal contact [ 45 ]. For compactness, the same threaded rods are used to assembly a generator with two thermoelectric modules, as shown in Figure 2 .…”