The new Gas engine from Dewerk is a four-stroke, spark-ignited gas engine operating on the Otto cycle and incorporating the lean-burn principle.
An important feature of this new gas engine in DEWERK portfolio is its exceptionally high power plant net electrical efficiency rating - more than 53% in combined-cycle mode.
Engine working principle of spark-ignited engines (DS)
The DS engines are spark-ignited lean-burn otto cycle gas engines. In this process, the gas is mixed with air before the inlet valves. During the intake period, gas is also fed into a small pre chamber, where the gas mixture is rich compared to the gas in the cylinder. At the end of the compression phase the gas/air mixture in the pre chamber is ignited by a spark plug. The flames from the nozzle of the pre chamber ignite the gas/air mixture in the whole cylinder. After the working phase the cylinder is emptied of exhaust and the process starts again.
The processes are described by:
· Process 0-1 a mass of air is drawn into piston/cylinder arrangement at constant pressure.
· Process 1-2 is an adiabatic (isentropic) compression of the air as the piston moves from bottom dead centre (BDC) to top dead centre (TDC).
· Process 2-3 is a constant-volume heat transfer to the working gas from an external source while the piston is at top dead centre. This process is intended to represent the ignition of the fuel-air mixture and the subsequent rapid burning.
· Process 3-4 is an adiabatic (isentropic) expansion (power stroke).
· Process 4-1 completes the cycle by a constant-volume process in which heat is rejected from the air while the piston is at bottom dead centre.
· Process 1-0 the mass of air is released to the atmosphere in a constant pressure process.
