Improved Heat Sink for Thermoelectric Energy Harvesting Systems

Abstract. This paper is focused on the improvement of the heat sink system of a thermal energy harvester by using organic and inorganic Phase Change Materials (PCM), considering solutions with the lowest environmental im-pact, as an alternative to well-known paraffin waxes. The proposed heat sink has been applied to the real case study of a thermoelectric energy har-vester to supply a wireless sensor node placed in the engine compartment of a vehicle and used for the continuous monitoring of the engine’s vibrations. Different hydrated salts (nitrate mixtures) have been evaluated as PCM, trough design of experiments techniques, working in a restrained well-tailored temperature ranges (±5°C) depending on mixtures’ composition, and compared with acetamide as best organic alternative. The realized PCM-based heat sink shown better performance compared with a classic heat sink in both steady-state and dynamic conditions.