Evaluation of Losses in a Diesel Engine Cycle and Improvement of Its Thermal Efficiency (Capabilities of Diesel Engine Combined Cycle)

Abstract

The Diesel engine and gas turbine combined cycle has an ability of getting much better thermal efficiency than any other type of cycles owing to its high temperature in the heat receiving process. Increase of expansion ratio in the diesel engine cycle minimizes the exergy loss in the process connecting diesel engine cycle and gas turbine one, and leads a thermal efficiency improvement about 4%. Although disuse of charge air cooling and furthermore heating of the charge air with the exhaust gas from turbine cause reduction of specific power output, they diminish the exergy losses in the heat receiving process in the cylinder and the exhaust process from turbine, and bring an improvenment of thermal efficiency by several %. The charge air temperature rise accompanying further improvement of the combined cycle thermal efficiency, requires the development of high efficiency gas turbine, and realization of the new methods for protecting diesel engine cylinder wall to higher temperature of working gas.