COMPARATIVE ANALYSIS OF NATURAL GAS ENGINE PARAMETERS WITH QUALITY AND QUANTITY CONTROL

Parameters of natural gas engines were calculated with the aim to determine the optimal way of their working process organization. Analysis of calculations results demonstrated that quality power level control ensured the improvement of parameters of investigated engines. Calculations showed that compared with the diesel engine, the gas engine with quantity power level control, internal mixture formation and glow plug ignition of the gas-air mixture ensured the decrease of СО2 emissions by 26.8%, and the natural gas engine with quality power level control, external mixture formation and gas-air mixture ignition by a small pilot portion of fine atomized diesel fuel supplied by a Common Rail fuel system – by 25.5%. Therefore, one can choose one or another method of diesel engine conversion for operation on gas fuel considering available technical opportunities and with minimal expenses.

EFFECT OF THE PILOT CHARGE INJECTION ADVANCE ANGLE ON THE OPERATING PARAMETERS OF A DUAL-FUEL COMPRESSION-IGNITION ENGINE FUELLED WITH BIOGAS

One of the ways of increasing the share of renewable fuels in the overall energy balance is to develop effective methods for using low calorific gaseous fuels, including biogas, to fuel combustion engines. This paper presents the results of research on the effect of changing the diesel fuel pilot charge injection advance angle on the operating parameters of a dual-fuel compression-ignition engine. The obtained results confirm the significant effect of the pilot charge injection advance angle on the engine torque value at a constant engine speed.

NUMERICAL INVESTIGATION ON THE EFFECTS OF GASOLINE AND HYDROGEN BLENDS ON SI ENGINE COMBUSTION

Even small amount additive (10…15% by volume from whole air amount) of hydrogen (H2) into spark ignition (SI) engines obviously effects ecological parameters and engine efficiency because of H2 exclusive properties. SI engine work process simulation was made using AVL Boost simulation software. Analysis of results showed that engine power depends a lot on H2 supply technique into engine; NOx amount in exhaust gases directly proportional to the amount of H2, however, making mixture leaner up to λ = 1.6, it is possible to reach significant NOx decrease. Increased amount of H2 as an additive in fuel, changes H/C ratio in fuel mixture, also hydrogen improves properties of the mixture (particularly lean) and combustion of hydrocarbons what can be a reason of decreased HC emissions in exhaust gases. Keyword(s): Hydrogen and gasoline mixture, engine efficiency, exhaust gases, nitrous oxides, hydrocarbons, simulation.