Abstract
Abstract The efficiency of thermoelectric cooler is not only affected by the properties of thermoelectric materials but also by the operating conditions and geometry of thermoelectric materials. In this research, we investigated the performance of the thermoelectric cooler by defining a geometric operation factor, IG, which is the applied current multiplied by the geometry of thermoelectric elements. We can calculate the optimized geometric operation factor to achieve the best performance of thermoelectric coolers. The effect of electric current distribution on the performance of thermoelectric devices is also discussed based on the theoretical analysis results. In this part, we build the 2D and 3D thermoelectric models using ANSYSTM FEA software, and explore the influence of non-uniform current in the thermoelectric elements. The simulation results indicate that the degree of current crowding in thermoelectric elements increases with decreasing length of TE elements. The longer TE elements result in larger temperature difference between both ends of TE elements. Therefore, there will be a marked conductive heat flowing from the hot side to the cold side, which degrades the performance of thermoelectric devices. According to the simulation results, it is found that the contact resistance effect causes the reduction of temperature difference. When the device loading is uniform current, the contact induced joule heat will raise the temperature at the cold side and decrease the performance of thermoelectric devices.