Selection of radiator

Radiator is an indispensable part of thermoelectric refrigeration system, so its importance must be emphasized here. Since the performance of all thermoelectric refrigeration devices is related to the temperature of the radiator, we need to be very careful in the selection and design of the radiator

1 The thermoelectric cooler works as a heat pump to transfer heat from one point to another, rather than an ordinary heat absorption process or a magic process of consuming heat. After power on, one side of the thermoelectric cooler will become cold and the other side will become hot. The heat of the cooled side will be transferred to the hot end, which is completely consistent with the thermodynamic process. In order to complete a heat flow cycle, the hot end of the thermoelectric cooler must be connected to a suitable radiator, so as to release the heat transferred from the cold end and the joule heat generated during device operation.
Radiator is an indispensable part of thermoelectric refrigeration system, so its importance must be emphasized here. Since the performance of all thermoelectric refrigeration devices is related to the temperature of the radiator, we need to be very careful in the selection and design of the radiator.
An ideal radiator needs the ability to absorb unlimited heat without causing an increase in temperature. But this is actually impossible to achieve, so the designer must choose a radiator that can keep the temperature increase within an acceptable range after absorbing all the heat from the thermoelectric refrigeration device. Here, although the so-called "the temperature increase of the radiator is within an acceptable range" is related to different application environments, since the cooling capacity of the thermoelectric cooler decreases with the increase of the temperature difference, the temperature increase of the radiator must be minimized during design. For the application of typical thermoelectric refrigerators circulating on the market at present, it is common for the radiator temperature to be 5-15 ℃ higher than the room temperature.
At present, there are many kinds of radiators to choose from, including natural convection, forced convection, and liquid cooling. The natural convection radiator can be used in very low power applications, especially when the working current of a small thermoelectric cooler is below 2 A. For most application conditions, the natural convection radiator can not meet the requirements of exhausting all the required heat. At this time, forced convection radiator or liquid cooling radiator is required.
The performance of radiator is generally measured by thermal resistance (Qs):
                Qs=(Ts - Ta )/ Q
Where Qs is the thermal resistance, in ℃/w;
Ts is the radiator temperature, in ℃;
Ta is the ambient or cold end temperature, in ℃;
Q is the heat input to the radiator, in w.