Study concerning the thermal energy balance in an internal combustion engine

Abstract

In this scientific report the steps for achieving the energy balance on a test engine Daewoo 1.6 liter in 4 cylinders, with 4 valves per cylinder, its power being77 kW, are presented. The engine was connected to a hydraulic brake during the tests. The energy balance was established, based on measurements applied on the stand test, focusing to determine the lost heat and to conceive a Sankey diagram, accordingly. Two sets of measurements were performed and based on them the heat losses were determined and two Sankey diagrams were depicted. The lost heat through the cooling fluid is determined by measuring the cooling water flow rate and its inlet and outlet temperature. The lost heat through the exhaust gases is determined by the difference between the enthalpy of the exhaust gases and the enthalpy of fresh air. The lost heat due to incomplete chemical combustion is determined by analyzing the composition of the exhaust gases. The measurements are centralized on a graphic user interface, supported by a NI Compact RIO platform.