Evaluation of electrical energy recovery from exhaust waste heat energy by thermoelectric generator under stationary operating conditions of an SI engine


Gürbüz H., Akçay H.

APPLIED THERMAL ENGINEERING, cilt.1, sa.1, ss.1-13, 2025 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 1 Sayı: 1
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1016/j.applthermaleng.2025.127715
  • Dergi Adı: APPLIED THERMAL ENGINEERING
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, PASCAL, Aerospace Database, Business Source Elite, Business Source Premier, Communication Abstracts, Compendex, INSPEC, Metadex, DIALNET, Civil Engineering Abstracts
  • Sayfa Sayıları: ss.1-13
  • Süleyman Demirel Üniversitesi Adresli: Evet

Özet

In this paper, the output performance of a three-layer rectangular-shaped thermoelectric generator (TEG) designed for exhaust waste heat recovery of a spark-ignition engine is investigated under stationary operating conditions and compared with the use of engine coolant in the cold-side heat exchangers (CS_hex). The temperatures of the TEM surface, voltage-current characteristics, power output, efficiency, and recovered fuel energy are evaluated at various engine speeds. Using lower-temperature tap water (TW) instead of engine coolant in CS_hex increases the temperature difference across the TEG, enhancing both power output and energy recovery. The results show that under TW conditions, the TEG produces between 22.75 and 137.79 W of electrical power, with efficiency ranging from 1.45 % to 1.97 %, and recovered fuel energy rate between 0.175 % and 0.375 %, depending on engine speed. When engine coolant is used, the maximum TEG power at 4500 rpm is 81 W and the recovered fuel energy rate is 0.275 %, which are 54 W and 0.1 % lower, respectively, compared to TW conditions. An approximately 70 % increase in TEG power is achieved using TW in CS_hex under stationary engine operation.