TY - JOUR
TI - Exhaust gas heat recovery through secondary expansion cylinder and water injection in an internal combustion engine
AU - Toosi Ali Nassiri
AU - Kakaee Amir Hassan
AU - Ebne-Abbasi Hazhir
JN - Thermal Science
PY - 2017
VL - 21
IS - 1
SP - 729
EP - 743
PT - Article
AB - To enhance thermal efficiency and increase performance of an internal combustion engine, a novel concept of coupling a conventional engine with a secondary 4-stroke cylinder and direct water injection process is proposed. The burned gases after working in a traditional 4-stroke combustion cylinder are transferred to a secondary cylinder and expanded even more. After re-compression of the exhaust gases, pre-heated water is injected at top dead center. The evaporation of injected water not only recovers heat from exhaust gases, but also increases the mass of working gas inside the cylinder, therefore improves the overall thermal efficiency. A 0-D/1-D model is used to numerically simulate the idea. The simulations outputs showed that the bottoming cycle will be more efficient at higher engines speeds, specifically in a supercharged/turbocharged engine, which have higher exhaust gas pressure that can reproduce more positive work. In the modeled supercharged engine, results showed that brake thermal efficiency can be improved by about 17%, and brake power by about 17.4%.