The Impact Analysis Of Thermodynamic Process Of Vehicle Engine On Exhaust Gas Energy

The energy of the engine exhaust equivalent to35%of the energy generated byfuel combustion, at present this part of the energy has not been effective used anddirect lost, resulting in wasted energy. People from the perspective of how to useeffectively exhaust gas energy, researching on the characteristic of the exhaust gasenergy and exhaust gas energy recycling methods. However, due to the workingprocess of the automobile engine cylinder is complicated,leading to the exhaustparameters show a transient volatility with different operation condition,makingrecycling process of exhaust gas energy relatively complex.The different time thechange of the flow field in cylinder and the cylinder substance in thermodynamicparameters (temperature, pressure, flow) of changes on the exhaust energy pulsecharacteristics have important influence. For the analysis of different exhaust energychange rule, it is necessary to combine the thermodynamic process in cylinder ofexhaust energy characteristics are analyzed.To establish a engine geometry model that include a air inlet, intake valve,acylinder,exhaust valve and a air outlet by using3D CAD software Pro/e. To establish asimulation platform of a gasoline engine working process,by the3D simulationsoftware AVL FIRE.Detailing calculation and analysis of four different rotational speedand the four different load in cylinder under thermal parameters and exhaust stateparameter change rule, under different working conditions, and to analyses thetemperature and pressure in cylinder on influence exhaust temperature, pressure, flowrate and the mass flow rate.On this basis,using the Matlab software to calculate theexhaust gas energy and to analysis the change rule of the various forms of exhaust gasenergy.Finally, combining the thermodynamic process in cylinder and the results of theanalysis on the influence of thermodynamic parameters of in cylinder to exhaust stateparameters. Respectively under load and speed characteristic to analysis the influenceon temperature and pressure on the various forms exhaust gas energy.It is found that the temperature and pressure in cylinder and exhaust temperature,pressure, flow velocity and mass flow rate is gradually increasing with the increase ofengine load. The kinetic energy, pressure energy and thermal energy of the exhaust gasis gradually increasing along with the increase of load.In the process of exhaust underhigh speed and high load, the change of the temperature in cylinder is great influence on exhaust gas temperature and is smaller influence on exhaust flow velocity. Thechange of the temperature in cylinder is great influence on exhaust gas temperature andpressure. The pressure energy and thermal energy of the exhaust gas can moreinfluence than the kinetic energy. With the the increase of engine speed,temperatureand pressure in cylinder and exhaust temperature, pressure, flow velocity and massflow rate is gradually increasing. The kinetic energy, pressure energy and thermalenergy of the exhaust gas is gradually increasing along with the increase of speed. Inthe process of exhaust under high speed and high load, the change of the pressure incylinder is great influence on exhaust gas pressure and exhaust flow velocity,issmaller influence on exhaust flow mass and temperature. The change of the pressurein cylinder is great influence on the kinetic energy. It is next to influence on exhaustpressure energy, the thermal energy of the exhaust gas exhaust can influence theminimum.