# Numerical Simulation on Thermoelectric Cooling of Core Power Devices in Air Conditioning
## 2 Simulations
In contrast, the maximum and average temperatures of the low-power-consumption power device were 369.1 K and 358.8 K, respectively (Figure 9c). The addition of the TEC resulted in a lower maximum temperature, but a higher average temperature compared to the air-cooling mode. This indicates that the TEC actively transports the heat from the high-power-consumption power device to the heat-sink fins, and then the heat is transferred to the low-power-consumption power device through the heat-sink fins. The temperature distribution on the heat-sink fins was basically the same as that under single air-cooling, with the maximum temperature of the heat-sink fins dropping from 363.8 K to 363.3 K and the average temperature rising from 348.5 K to 348.6 K (Figure 9d). The above simulation results demonstrate that the temperature of the power device was  
Figure 9: Steady-state temperature distribution under TEC forced cooling and air-cooling: (**a**) the overall system, (**b**) the high-power-consumption power devices, (**c**) the low-power-consumption power devices, and (**d**) the heat-sink fins. well-controlled after the addition of the TEC, which is crucial for optimizing performance and extending the service life of these devices. The previous research proved that the addition of the TEC under a constant operating current can effectively control the temperature of power devices. To further explore the reliability of TEC temperature control, the effect of the TEC on the operating temperature of power devices under different operating currents was experimentally studied. We systematically simulated the temperature field of the system under different TEC working currents. The average temperature of the high-power-consumption power device, low-power-consumption power device, and the heat-sink fins in the system varied with the working current of the TEC, as shown in Figure 10. It is evident that when the working current of the TEC was less than 5 A, the TEC had no active cooling effect on the power devices, even if the temperature was higher than that under air-cooling. This is because the cooling capacity of the TEC is related to the working current, and the TEC itself can also be regarded as a thermal resistance, of which the resistance varies with the working current in the heat transfer path. When the active cooling capacity minus the Joule heat is less than the original thermal conductivity, the thermal resistance effect will be realized. From the simulation results, the minimum working current of the TEC to achieve a cooling effect should reach 5 A under this working condition. When the working current of the TEC is further increased to 7.5 A and 10 A, the temperature of the cooled high-power-consumption power device can be further reduced to 326.5 K and 292.9 K, respectively, resulting in a significant improvement in temperature control. At the same time, the nearby low-power-consumption power devices and heat-sink fins will heat up because of the heat pump effect of the TEC, and the increase of the temperature of the heat-sink fins will also help to improve the air-cooled heat transfer.