Performance of a Thermoelectric Cooling Module under Thermodynamic Second–Law Analysis

This paper presents an experimental analysis based on the energy and exergy concepts to evaluate the cooling performance of a thermoelectric–based refrigeration system. This system was composed of a cooling box made from expanded polystyrene with air load and a commercial TEC1 – 12706 device cooled under forced–air convection, with heat transfer assemblies formed by two pin–fin heat sinks and fans. Considering a testing time of 8 minutes, we first investigated the coefficient of performance COP<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TEC</inf>, the direct-run efficiency η<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TEC</inf> and the absorbed heat at the cold side of the thermoelectric cooler Q<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</inf>. The performance parameters COP<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TEC</inf> and Q<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</inf> decreased linearly under refrigeration temperature Tr decreasing, with non–linear η<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TEC</inf> increasing along the cooling time. We established maximum exergy efficiency values around 0.707 at external and internal irreversibilities between 44.6 – 44.1 W for COP<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TEC</inf> values between 0.559 – 0.605 during an optimal cooling temperature domain between -0.5°C and 4.1°C.