Exhaust Energy Recovery using Thermoelectric Power Generation from a Thermally Insulated Diesel Engine

• Published in: International journal of green energy 2013-01, Vol.10 (10), p.1056-1071
• Main Authors: Karthikeyan, B., Kesavaram, D., Ashok Kumar, S., Srithar, K.
• Format: Article
• Language: English
• Subjects: Aluminum titanate; Applied sciences; Diesel engine; Energy; Energy. Thermal use of fuels; Engines and turbines; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Low heat rejection; Seebeck effect; Thermo electric module; Waste heat recovery
• ISSN: 1543-5075; 1543-5083
• DOI: 10.1080/15435075.2012.740608

Over two-thirds energy of fuel consumed by a diesel engine is discharged to the surroundings. The application of thermal barrier coatings reduces the heat losses through the engine cooling systems and increases the efficiency and exhaust energy. This energy available in the exit stream of the low heat rejection (LHR) engine goes waste, if not recovered. In the present work, the combustion chamber of a single cylinder diesel was coated with aluminum titanate. A waste heat recovery system was developed using a thermoelectric power generation module. Experiments were carried out on the conventional diesel engine and insulated (400-μm coating thickness on the cylinder head, valves and 300, 400, and 500-μm thicknesses on the piston top surface) diesel engine. The highest brake thermal efficiency of 26% was obtained with the 400-μm thickness of alumina-titania insulation in the combustion chamber, as compared with that of the standard engine. A maximum module efficiency of 2.87% was obtained with the 400-μm thickness insulation. A maximum of 20.6% of waste heat available in the exhaust was recovered at full-load condition with the insulation of 400-μm thickness.